PHARMACOLOGY MASTER Cardiovascular, Renal & Hemostasis

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🗺️ Interactive High-Yield Schematic Diagrams

Click any highlighted drug marker or pathway component in the vector diagrams below to open detailed pharmacological mechanisms, ECG changes, indications, adverse reactions, and exam traps.

Cardiac Action Potential & Vaughan Williams Antiarrhythmic Sites

Interactive cellular electrophysiology showing ventricular vs nodal action potentials and drug targets

Interactive SVG
+20 mV 0 mV -40 mV (Threshold) -90 mV (RMP) VENTRICULAR MYOCYTE ACTION POTENTIAL (Non-Pacemaker) SA / AV NODAL (Pacemaker) ACTION POTENTIAL Phase 0 Fast INa Influx Phase 1 Transient Ito (K+ out) Phase 2 (Plateau) ICa-L influx balance with IK Phase 3 IKr / IKs Repolarization Phase 4 (Resting -90mV) CLASS IA (Na+ block) Quinidine, Procainamide CLASS IB (Na+ block) Lidocaine, Mexiletine CLASS IC (Na+ block) Flecainide, Propafenone CLASS III (K+ block) Amiodarone, Sotalol Phase 4 (Funny Current If) Slow spontaneous depolarization Phase 0 (Ca2+) ICa-L influx (NO fast Na!) Phase 3 IK efflux repolarization CLASS II (Beta-Blockers) Metoprolol, Bisoprolol IVABRADINE (If inhibitor) Slows sinus HR exclusively CLASS IV (Ca2+ block) Verapamil, Diltiazem ADENOSINE (A1 agonist) K+ outward / transient AV stop EXAM QUICK SUMMARY (VAUGHAN WILLIAMS): 1A (Quinidine): Moderate Na+ block, prolongs APD/QT. | 1B (Lidocaine): Weak Na+ block, shortens APD, ischemic VT only. | 1C (Flecainide): Marked Na+ block, no APD change. Class II (Beta-blockers): Decrease phase 4 slope in AV/SA node. | Class III (Amiodarone): Prolong Phase 3 & QT. | Class IV (Verapamil): Slow AV conduction.

Coagulation Cascade & Antithrombotic Drug Targets

Interactive pathways of Intrinsic, Extrinsic, Common cascade, Platelet aggregation, and Fibrinolysis

Interactive SVG
INTRINSIC PATHWAY (aPTT) EXTRINSIC PATHWAY (PT / INR) XII XI IX + VIIIa Tissue Factor (III) VIIa FACTOR Xa (+ Va) THROMBIN (IIa) FIBRIN MESH (Ia) [Clot] UFH (Heparin) ATIII -> IIa & Xa (1:1) LMWH (Enoxaparin) ATIII -> Xa >> IIa (4:1) RIVAROXABAN Direct Factor Xa Inhibitor WARFARIN / ACENO. Blocks VKORC1 Factors II, VII, IX, X ALTEPLASE (rt-PA) Plasminogen -> Plasmin AMINOCAPROIC ACID Inhibits Plasmin (Antidote) PLATELET TARGETS: • Aspirin: Irreversible COX-1 (TXA2 ⬇) • Clopidogrel: P2Y12 ADP receptor blocker • Tirofiban: GPIIb/IIIa cross-link blocker ANTIDOTES / REVERSAL: • Protamine: Heparin antidote • Vit K1 (Phytomenadione): Warfarin antidote (+ 4F-PCC) • Etamsylate: Capillary hemostasis

Renin-Angiotensin-Aldosterone System (RAAS) & Anti-HTA Targets

Interactive endocrine axis showing drug inhibition points, bradykinin pathways, and clinical consequences

Interactive SVG
LIVER Angiotensinogen KIDNEY (JG Apparatus) RENIN Beta-1 Blockers (Inhibit Renin) ALISKIREN (Renin Inhibitor) Angiotensin I ACE ACE INHIBITORS Captopril, Enalapril, Lisinopril Bradykinin ⬆ -> Cough & Angioedema ANGIOTENSIN II AT1 RECEPTOR ARBs (AT1 Blockers) Losartan, Valsartan (No cough!) Arteriolar Vasoconstriction SVR ⬆ | Afterload ⬆ | BP ⬆ ADRENAL CORTEX ALDOSTERONE SPIRONOLACTONE MRA (Spares K+, blocks remodeling) ARNI (Sacubitril + Valsartan / Entresto) • Sacubitril: Inhibits Neprilysin -> ANP/BNP ⬆ (Natriuresis, Vasodilation) • Valsartan: Blocks AT1 receptor (Blocks Ang II remodeling) ⚠️ MUST allow 36h washout from ACEi before starting ARNI (Angioedema!) ⚠️ HIGH-YIELD RAAS EXAM TRAPS: 1. Pregnancy: ACEi & ARBs are strictly teratogenic (renal dysgenesis, skull defects, oligohydramnios). 2. Bilateral Renal Artery Stenosis: GFR drops precipitously -> Acute Renal Failure.

Nephron Architecture & Diuretic Sites of Action

Interactive nephron segments showing transport channels, ion effects, and diuretic classes

Interactive SVG
GLOM PROXIMAL TUBULE (PCT) ACETAZOLAMIDE (CAI) HCO3- & Na+ excretion LOOP OF HENLE H2O reabsorption LOOP DIURETICS (TAL) Furosemide, Torsemide Blocks NKCC2 (Na+/K+/2Cl-) EARLY DISTAL TUBULE (DCT) THIAZIDES (Early DCT) Indapamide, HCTZ Blocks NCC (Na+/Cl-) COLLECTING DUCT (CD) K+-SPARING DIURETICS (CD) • Spironolactone: Aldosterone Rec. Blocker • Amiloride/Triamterene: ENaC Blockers Spares K+ & H+ (Hyperkalemia risk) ION EXCRETION MATRIX (MUST MEMORIZE): LOOP (Furosemide): Na+ ⬆⬆, K+ ⬆, Cl- ⬆, Ca2+ ⬆ (Wasted!), Mg2+ ⬆ THIAZIDE (Indapamide): Na+ ⬆, K+ ⬆, Cl- ⬆, Ca2+ ⬇ (Reabsorbed!) K+-SPARING (Spirono): Na+ ⬆ (mild), K+ ⬇ (Retained!), H+ ⬇ (Acidosis) 💡 Mnemonic: 'Loops LOSE Calcium, Thiazides TAKE (save) Calcium'

Shock Differential & Vasoactive Decision Tree

Interactive hemodynamic profiles (CO, SVR, CVP/PCWP) and adrenergic drug selector

Interactive SVG
ACUTE HYPOTENSION / SHOCK (MAP < 65) 1. HYPOVOLEMIC SHOCK • Preload (CVP/PCWP): ⬇⬇ (Very Low) • Cardiac Output (CO): ⬇ • SVR (Afterload): ⬆⬆ (Vasoconstriction) TREATMENT: IV Crystalloids (0.9% NaCl, Ringer) / Blood / Colloids 2. CARDIOGENIC SHOCK • Preload (PCWP): ⬆⬆ (Congestion / Edema) • Cardiac Output (CO): ⬇⬇ (Pump Failure) • SVR (Afterload): ⬆⬆ TREATMENT: Dobutamine (Inotrope) + Norepinephrine (if SBP<70) 3. DISTRIBUTIVE (Septic/Anaph) • Preload (CVP): ⬇ or Normal • Cardiac Output (CO): ⬆ (Warm Shock) or Normal • SVR (Afterload): ⬇⬇ (Severe Vasodilation) TREATMENT: Norepinephrine (1st Line) / Epinephrine (Anaphylaxis) VASOACTIVE DRUG RECEPTOR PROFILES (EXAM MATRIX): Norepinephrine (Noradrenaline): alpha-1 +++, beta-1 ++, beta-2 minimal. -> First-line in septic shock (potent vasoconstrictor). Epinephrine (Adrenaline): alpha-1 +++, beta-1 +++, beta-2 +++. -> First-line in anaphylaxis (bronchodilation + vasoconstriction). Dobutamine: beta-1 +++, beta-2 +, alpha-1 minimal. -> First-line inotrope in cardiogenic shock (CO ⬆, mild SVR ⬇). Dopamine (Dose-Dependent): Low (0.5-3 mcg): D1 (renal dilation) | Mid (3-10 mcg): beta-1 (inotropy) | High (>10 mcg): alpha-1 (vasoconstriction). Phenylephrine: Pure alpha-1 +++. No beta activity. -> Vasoconstriction with reflex vagal bradycardia.

Cardiac Glycoside Mechanism & Digitalis Toxicity Cascade

From Na+/K+ ATPase inhibition to positive inotropy, delayed afterdepolarizations (DADs), and management

Interactive SVG
THERAPEUTIC MECHANISM (INOTROPY) 1. Inhibition of Sarcolemmal Na+/K+-ATPase Digoxin/Strophanthin competitively blocks the K+ binding site on the pump. 2. Intracellular [Na+] Accumulates Intracellular sodium concentration rises from ~10 mM to ~20 mM. 3. 3Na+ / 1Ca2+ Exchanger (NCX) Slows / Reverses Decreased driving force for Ca2+ extrusion -> Intracellular [Ca2+] rises. 4. Sarcoplasmic Reticulum (SERCA) Ca2+ Loading More Ca2+ stored in SR -> Huge Ca2+ release during systole. RESULT: Powerful Positive Inotropy + Cardiac Output ⬆ CENTRAL VAGAL STIMULATION: Increases vagal tone -> Negative Chronotrope & Dromotrope (Rate control in AFib) DIGITALIS TOXICITY CASCADE & CURE PREDISPOSING TRIGGERS (EXAM TRAP): • Hypokalemia (low K+ allows more digoxin binding) | Hypomagnesemia | Hypercalcemia SYMPTOMS & ECG HALLMARKS: • GIT: Anorexia, Nausea, Vomiting (earliest sign) • Vision: Xanthopsia (yellow-green visual halos), blurred vision • ECG: 'Salvador Dali mustache' ST depression, PVCs, Bidirectional VT TREATMENT PROTOCOL (STEP-BY-STEP): 1. STOP Digoxin and K+-wasting diuretics immediately. 2. Potassium Chloride IV/oral (if K+ < 4.0 and no high-grade AV block). 3. Magnesium Sulfate IV (stabilizes myocardial membrane). 4. Lidocaine or Phenytoin (antiarrhythmic of choice for ventricular VT/PVCs). 5. Atropine (for severe bradycardia or AV block). 6. Digibind / DigiFab (Fab fragments) for life-threatening toxicity!

📸 Official Textbook Classifications (Faculty Curriculum Reference)

Direct reproduction and interactive breakdowns of the official textbook classification trees from Page 293 (Heart Failure Preparations) and Page 228 (Dose-Dependent Effects of Dopamine).

Official Curriculum Reference • Page 293

Preparations Used in Heart Failure

Medicinal remedies with influence on the cardiovascular system that improve cardiac work and eliminate venous stasis

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I. POSITIVE INOTROPIC DRUGS

Direct myocardial contractility enhancers

1. Membrane Na+/K+-ATPase Inhibitors (Cardiac Glycosides)
Strophanthin Corglycon Digoxin Digitoxin
2. Cardiostimulators (Dopaminergic & Beta-Adrenomimetics)
Dopamine Dobutamine Isoprenaline (Isoproterenol) Dopexamine Epinephrine (Adrenaline)
3. Phosphodiesterase (PDE) Inhibitors
• Bipyridines:
Amrinone (Inamrinone) Milrinone Enoximone
• Methylxanthines:
Aminophylline Theophylline
4. Contractile Protein Calcium Sensitizers
Levosimendan
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II. REMEDIES REDUCING PRE-LOAD & AFTERLOAD

Indirect cardiotonics: Vasodilators, Diuretics & Neurohormonal blockers

A. Vasodilators by Pharmacological Group:
  • Musculotropic Vasodilators: Nitroglycerin, Hydralazine, Minoxidil, Sodium nitroprusside, Isosorbide dinitrate, Isosorbide mononitrate.
  • Alpha-Adrenergic Blockers: Phentolamine, Prazosin, Terazosin, Doxazosin.
  • Calcium Channel Blockers: Nifedipine, Amlodipine, Nicardipine, Verapamil, Diltiazem.
  • Angiotensin-Converting Enzyme (ACE) Inhibitors: Saralasin, Captopril, Enalapril, Lisinopril, Fosinopril, Trandolapril, Ramipril, Quinapril, Spirapril, etc.
  • Angiotensin II Receptor Blockers (ARBs): Losartan, Irbesartan, Valsartan, Candesartan.
  • Various Vasodilator Groups: Bendazol, Papaverine, Magnesium sulfate, etc.
B. Diuretics:
Furosemide Ethacrynic acid Hydrochlorothiazide Spironolactone Triamterene Indapamide Xipamide
C. Various Groups (Beta-Adrenoblockers):
Atenolol Metoprolol Talinolol Bisoprolol Nebivolol Carvedilol Propranolol
Official Curriculum Reference • Page 228

Dose-Dependent Hemodynamic Effects of Dopamine

Remedies acting on the peripheral autonomic nervous system • Pharmacodynamic dose titration

Small Doses (Low Dose) 0.5 - 2 mcg/kg/min

Dopaminergic Receptor (D1) Phase

Excitation of vascular dopamine D1 receptors predominates:

  1. Positive inotropic effect WITHOUT tachycardia
  2. Selective renal and mesenteric vasodilation
  3. Improvement of systemic and organ hemodynamics
  4. Increased diuresis and natriuresis (renal protective flow)
  5. Correction of arterial hypotension of hypertonic/cardiac type (preserves renal perfusion)
  6. High clinical efficacy in acute heart failure
Medium Doses (Intermediate) 2 - 10 mcg/kg/min

Beta-1 Adrenergic Phase (The 4 Positive Tropisms)

Excitation of myocardial Beta-1 adrenoreceptors predominates:

  1. Positive inotropic effect (+): increases force of contraction & stroke volume
  2. Positive chronotropic effect (+): accelerates heart rate (tachycardia begins)
  3. Positive dromotropic effect (+): speeds AV nodal conduction velocity
  4. Positive bathmotropic effect (+): enhances myocardial excitability
  5. High efficacy in acute heart failure & cardiogenic shock
Large Doses (High Dose) > 10 mcg/kg/min

Alpha-Adrenergic Vasopressor Phase

Excitation of vascular Alpha-1 & Alpha-2 receptors predominates:

  1. Intense generalized arterio- and venoconstriction
  2. Marked increase in systemic vascular resistance (SVR) and arterial blood pressure
  3. Reduction of peripheral microcirculation with risk of tissue hypoxia, ischemia, acidosis, and necrosis
  4. Oligo- or anuria (due to severe renal vasoconstriction)
  5. Efficacy in hypotonic or mixed-type arterial hypotension (vasomotor collapse, septic shock)
Cardiology PDF 1 Questions 1 - 8 (Glycosides, Digitalization, Inotropes, GDMT)

Module 1: Heart Failure & Cardiotonic Pharmacology

1. Pathophysiological Targets in Heart Failure

Heart failure (HF) occurs when the heart cannot pump sufficient blood to meet the metabolic demands of tissues or can do so only from elevated filling pressures. Pharmacotherapy targets two main aspects: (A) Hemodynamic loading (Pre-load and Post-load) and (B) Myocardial contractility (Inotropy) and Neurohormonal remodeling.

Pre-load Reducers (Venodilators & Diuretics)

  • Venous Dilators: Nitroglycerin, Isosorbide dinitrate -> Increase venous capacitance, decrease venous return, decrease left ventricular end-diastolic pressure (LVEDP) and pulmonary capillary wedge pressure (PCWP).
  • Diuretics: Furosemide, Torsemide -> Natriuresis and diuresis reduce circulating blood volume and pulmonary/systemic venous congestion.

Post-load Reducers (Arteriodilators)

  • Arteriolar Dilators: Hydralazine, Dihydropyridine CCBs -> Decrease systemic vascular resistance (SVR), facilitating left ventricular ejection and increasing stroke volume without increasing oxygen demand.
  • Balanced Veno- & Arteriodilators: ACE inhibitors, ARBs, ARNI, Sodium nitroprusside -> Simultaneously reduce both preload and afterload.

2. Cardiotonic Glycosides (Digitalis Derivatives)

Drug Polarity & Solubility Oral Absorption Latency (Onset) Duration of Action Elimination / Metabolism
Strophanthin (G / K) Hydrophilic (High polarity) Virtually 0% (IV only) Fast (5 - 10 min) Short (1 - 3 days) 100% renal excretion unchanged; lowest cumulative risk
Digoxin Intermediate polarity 60 - 80% (Oral & IV) Intermediate (30 min IV, 1-2h Oral) Moderate (3 - 6 days, t1/2 ~36h) 70-80% renal filtration; moderate cumulative risk
Digitoxin Lipophilic (Low polarity) 90 - 100% (Oral) Slow (2 - 4 hours) Long (14 - 21 days, t1/2 ~7 days) Hepatic metabolism (enterohepatic circulation); highest accumulation
⚡ Mechanism of Action & Pharmacological Effects of Glycosides:
  1. Positive Inotropic (+): Reversibly inhibits sarcolemmal Na+/K+-ATPase -> intracellular Na+ rises -> decreases Ca2+ efflux via 3Na+/1Ca2+ exchanger (NCX) -> intracellular Ca2+ accumulates in sarcoplasmic reticulum -> increased systolic Ca2+ release -> enhanced force and velocity of myocardial contraction.
  2. Negative Chronotropic (-): Increases central vagal tone (parasympathomimetic) and sensitizes carotid baroreceptors -> slows SA node firing rate.
  3. Negative Dromotropic (-): Prolongs refractory period and slows conduction velocity through the AV node -> slows ventricular rate in atrial fibrillation/flutter.
  4. Positive Bathmotropic (+): Enhances ectopic excitability and automaticity at toxic levels due to intracellular Ca2+ overload (delayed afterdepolarizations / DADs).

3. Principles of Digitalization (Administration Regimens)

  • Rapid Digitalization: Full digitalization dose given over 24-36 hours (IV Strophanthin or Digoxin in divided doses). Indicated only in emergency acute HF or rapid tachyarrhythmias under intensive ECG monitoring. High toxicity risk!
  • Moderate (Gradual) Digitalization: Digitalizing dose divided over 3-5 days (Digoxin 0.25-0.5 mg BID-TID), followed by daily maintenance.
  • Slow (Maintenance-Only) Digitalization: Give regular daily maintenance dose (Digoxin 0.125-0.25 mg/day) from day 1 without loading dose. Steady-state plasma concentration is reached after 4-5 half-lives (~7-10 days). Safest and standard outpatient approach today.

4. Digitalis Intoxication & Antidote Protocol

Digoxin has a very narrow therapeutic window (therapeutic: 0.5 - 0.9 ng/mL; toxicity typically at > 2.0 ng/mL). Toxicity is strongly precipitated by hypokalemia, hypomagnesemia, hypercalcemia, renal impairment, and drug interactions (Quinidine, Verapamil, Amiodarone).

⚠️ Clinical Manifestations & ECG of Digoxin Toxicity:
  • Extracardiac: GIT (earliest sign): Anorexia, nausea, vomiting, abdominal pain, diarrhea. Neurological/Visual: Xanthopsia (yellow-green visual halos), blurred vision, scotomas, confusion, fatigue, headaches.
  • Cardiac Arrhythmias: Ventricular premature contractions (bigeminy/trigeminy - hallmark), junctional tachycardia, bidirectional ventricular tachycardia, sinus bradycardia, AV blocks.
  • ECG Signs: 'Salvador Dali mustache' (scooped sagging ST depression), T-wave flattening/inversion, shortened QT interval, prolonged PR interval.

Stepwise Treatment of Digitalis Toxicity:

  1. Immediately DISCONTINUE Digoxin and any potassium-wasting diuretics (furosemide/thiazides).
  2. Administer Potassium Chloride: If serum K+ is low or normal and NO advanced AV block exists (target K+ 4.5-5.0 mmol/L). Potassium displaces digitalis from the Na+/K+ pump.
  3. Magnesium Sulfate IV (1-2 g): Stabilizes myocardial membrane, especially for polymorphic ventricular arrhythmias.
  4. Antiarrhythmics: Lidocaine (Class IB) or Phenytoin (Class IB) are drugs of choice for ventricular arrhythmias—they suppress triggered automaticity without depressing AV conduction!
  5. Atropine Sulfate (0.5-1.0 mg IV): For symptomatic bradycardia or 2nd/3rd degree AV block.
  6. Digoxin-specific Fab Antibody Fragments (Digibind / DigiFab): Definitive antidote for life-threatening toxicity (severe hyperkalemia >5.5 mmol/L, intractable ventricular arrhythmias, or massive acute ingestion >10 mg).
  7. Contraindicated: Electrical DC cardioversion (can trigger intractable VF) and IV Calcium (triggers 'stone heart' contracture)!

5. Non-Glycosidic Cardiotonics & Inotropes

PDE-3 Inhibitors (Milrinone, Enoximone, Inamrinone)

  • Mechanism: Inhibits phosphodiesterase-3 -> prevents cAMP breakdown -> increases cAMP in cardiomyocytes (positive inotropy) AND in vascular smooth muscle (vasodilation). Termed 'Inodilators'.
  • Effects: Increases cardiac output while reducing preload (venodilation) and afterload (arteriodilation).
  • Indications: Short-term IV support in acute decompensated HF or cardiogenic shock refractory to other agents.
  • Adverse Effects: Ventricular arrhythmias, hypotension, thrombocytopenia (inamrinone). Long-term oral use increases mortality!

Calcium Sensitizers (Levosimendan)

  • Mechanism: Binds to cardiac troponin C in a Ca2+-dependent manner, stabilizing its active conformation -> enhances contractile force WITHOUT increasing intracellular Ca2+ levels or myocardial oxygen consumption! Also opens ATP-sensitive K+ channels (K_ATP) causing vasodilation.
  • Indications: Short-term management of acute decompensated severe heart failure (ADHF) where conventional inotropes fail.
  • Benefits: No increase in myocardial oxygen demand; lower arrhythmogenic risk than PDE inhibitors or catecholamines.

Adrenergic & Dopaminergic Cardiostimulators

  • Dobutamine: Synthetic catecholamine; potent selective Beta-1 agonist > Beta-2 / Alpha-1. Increases myocardial contractility (stroke volume) with modest chronotropic effect and mild vasodilation. Drug of choice in cardiogenic shock with low cardiac output and preserved systolic BP.
  • Dopamine: Natural catecholamine precursor with dose-dependent receptor selectivity:
    • Low Dose (0.5 - 3 mcg/kg/min): Stimulates vascular D1 receptors -> renal, mesenteric, and coronary vasodilation -> increases renal blood flow and diuresis.
    • Intermediate Dose (3 - 10 mcg/kg/min): Stimulates cardiac Beta-1 receptors -> increases contractility and cardiac output.
    • High Dose (> 10 mcg/kg/min): Stimulates vascular Alpha-1 receptors -> intense systemic vasoconstriction -> increases SVR and blood pressure.

6. Guideline-Directed Medical Therapy (GDMT) for Chronic HFrEF

Current international guidelines mandate the 'Fantastic Four' foundational pillar therapy to improve survival and reduce hospitalizations:

  1. ARNI (Sacubitril/Valsartan) or ACEi/ARB: Neurohormonal RAAS blockade and natriuretic peptide augmentation.
  2. Evidence-Based Beta-Blocker: Bisoprolol, Metoprolol succinate, or Carvedilol (reduces catecholamine toxicity, prevents sudden cardiac death).
  3. Mineralocorticoid Receptor Antagonist (MRA): Spironolactone or Eplerenone (prevents aldosterone-mediated myocardial fibrosis).
  4. SGLT2 Inhibitor: Dapagliflozin or Empagliflozin (osmotic diuresis, prevents remodeling, improves myocardial energetics).
  5. Loop Diuretics (Furosemide): Added PRN for fluid retention and symptom relief (does not decrease mortality on its own).

📸 Official Faculty Textbook Classification Tree (Page 293 Reference):

Official Curriculum Reference • Page 293

Preparations Used in Heart Failure

Medicinal remedies with influence on the cardiovascular system that improve cardiac work and eliminate venous stasis

⚡

I. POSITIVE INOTROPIC DRUGS

Direct myocardial contractility enhancers

1. Membrane Na+/K+-ATPase Inhibitors (Cardiac Glycosides)
Strophanthin Corglycon Digoxin Digitoxin
2. Cardiostimulators (Dopaminergic & Beta-Adrenomimetics)
Dopamine Dobutamine Isoprenaline (Isoproterenol) Dopexamine Epinephrine (Adrenaline)
3. Phosphodiesterase (PDE) Inhibitors
• Bipyridines:
Amrinone (Inamrinone) Milrinone Enoximone
• Methylxanthines:
Aminophylline Theophylline
4. Contractile Protein Calcium Sensitizers
Levosimendan
🛡️

II. REMEDIES REDUCING PRE-LOAD & AFTERLOAD

Indirect cardiotonics: Vasodilators, Diuretics & Neurohormonal blockers

A. Vasodilators by Pharmacological Group:
  • Musculotropic Vasodilators: Nitroglycerin, Hydralazine, Minoxidil, Sodium nitroprusside, Isosorbide dinitrate, Isosorbide mononitrate.
  • Alpha-Adrenergic Blockers: Phentolamine, Prazosin, Terazosin, Doxazosin.
  • Calcium Channel Blockers: Nifedipine, Amlodipine, Nicardipine, Verapamil, Diltiazem.
  • Angiotensin-Converting Enzyme (ACE) Inhibitors: Saralasin, Captopril, Enalapril, Lisinopril, Fosinopril, Trandolapril, Ramipril, Quinapril, Spirapril, etc.
  • Angiotensin II Receptor Blockers (ARBs): Losartan, Irbesartan, Valsartan, Candesartan.
  • Various Vasodilator Groups: Bendazol, Papaverine, Magnesium sulfate, etc.
B. Diuretics:
Furosemide Ethacrynic acid Hydrochlorothiazide Spironolactone Triamterene Indapamide Xipamide
C. Various Groups (Beta-Adrenoblockers):
Atenolol Metoprolol Talinolol Bisoprolol Nebivolol Carvedilol Propranolol
Electrophysiology PDF 1 Question 9 (Classes I - IV, Adenosine, K, Mg, Atropine, Glycosides)

Module 2: Antiarrhythmic Drugs (Vaughan Williams & Beyond)

1. Vaughan Williams Antiarrhythmic Classification

Class Primary Mechanism Representative Drugs Effect on APD / ERP ECG Hallmark Primary Clinical Indications
Class IA Moderate Na+ channel block + moderate K+ channel block Quinidine, Procainamide, Disopyramide Prolongs APD & ERP Widened QRS & Prolonged QT Atrial and ventricular arrhythmias. Procainamide = WPW syndrome drug of choice.
Class IB Weak/Fast Na+ channel block (rapid kinetics, ischemic selective) Lidocaine, Mexiletine, Phenytoin Shortens APD & ERP No change or shortens QT Ventricular arrhythmias ONLY (post-MI VT/VF, digitalis-induced VT). Ineffective in SVT!
Class IC Potent/Slow Na+ channel block (marked Phase 0 depression) Flecainide, Propafenone No effect on APD Marked QRS widening, prolonged PR Supraventricular arrhythmias, AFib cardioversion in structurally normal hearts ('pill-in-the-pocket').
Class II Beta-adrenoreceptor blockade (inhibits Phase 4 SA/AV slope) Metoprolol, Bisoprolol, Propranolol, Esmolol Decreases automaticity, slows AV conduction Prolonged PR interval, bradycardia Sympathetic-driven arrhythmias, rate control in AFib/AFlutter, post-MI prevention of sudden cardiac death.
Class III Potassium channel block (inhibits IKr / IKs repolarizing currents) Amiodarone, Sotalol, Dronedarone, Dofetilide, Ibutilide Markedly prolongs APD & ERP Prolonged QT interval Broad spectrum: Life-threatening VT/VF, rhythm control in AFib/AFlutter. Sotalol has Class II activity.
Class IV L-type Calcium channel block (slows Phase 0 in SA & AV nodes) Verapamil, Diltiazem (Non-DHP CCBs) Slows AV conduction, increases AV ERP Prolonged PR interval Acute termination of PSVT (AVNRT/AVRT), rate control in AFib and Atrial Flutter.
⚠️ THE CAST TRIAL WARNING (Crucial Exam Concept):

The Cardiac Arrhythmia Suppression Trial (CAST) proved that Class IC antiarrhythmics (Flecainide, Encainide) in patients with prior myocardial infarction or structural heart disease significantly increased mortality and sudden cardiac death due to lethal proarrhythmia! Class IC drugs are strictly contraindicated in post-MI and ischemic heart disease.

2. Amiodarone Multi-Channel Pharmacology & Systemic Toxicities

Amiodarone is an exceptionally broad-spectrum antiarrhythmic containing iodine in its structure. It combines Class I, II, III (dominant), and IV actions, along with non-competitive alpha-blocking properties.

Pharmacokinetics:

  • Enormous volume of distribution (>60 L/kg) due to extensive lipophilic tissue accumulation (adipose, lungs, liver).
  • Elimination half-life is extraordinarily prolonged: 40 to 60 days!
  • Requires prolonged high-dose oral loading (600-800 mg/day for 1-2 weeks) before reaching therapeutic steady state.

Organ Toxicities (Mnemonic: 'BITCHES'):

  • Pulmonary: Interstitial pulmonary fibrosis / pneumonitis (most lethal toxicity; monitor annual chest X-ray and PFTs).
  • Thyroid: Both hypothyroidism (blocks T4->T3 conversion, Wolff-Chaikoff effect) and hyperthyroidism (Jod-Basedow phenomenon).
  • Ocular: Corneal microdeposits (asymptomatic, reversible) & optic neuropathy.
  • Dermatological: Photosensitivity and slate-blue / blue-gray skin discoloration.
  • Hepatic: Elevated transaminases, hepatitis, cirrhosis.
  • Cardiac: Symptomatic sinus bradycardia, heart blocks, QT prolongation (though Torsades de Pointes is surprisingly rare <1%).

3. Other Essential Antiarrhythmic Groups

A. Adenosine (Nucleoside Analog)

  • Mechanism: Stimulates adenosine A1 receptors on AV nodal myocytes -> couples to Gi protein -> activates outward K+ channels (IK-Ado) causing hyperpolarization AND inhibits adenylate cyclase / L-type Ca2+ channels -> causes profound, transient conduction block across the AV node.
  • Pharmacokinetics: Ultra-short half-life (< 10 seconds) due to rapid cellular uptake and metabolism by adenosine deaminase. Administered as a rapid IV bolus into a large antecubital vein followed immediately by a rapid saline flush.
  • Indications: Drug of absolute first choice for acute conversion/termination of Paroxysmal Supraventricular Tachycardia (AVNRT and AVRT).
  • Interactions & Traps: Antagonized by methylxanthines (caffeine, theophylline); potentiated by dipyridamole. Contraindicated in 2nd/3rd degree AV block and severe asthma.

B. Magnesium Sulfate

  • Mechanism: Modulates Na+/K+ ATPase, sodium channels, and L-type calcium channels; suppresses early afterdepolarizations (EADs).
  • Indications: Drug of Choice for Torsades de Pointes (polymorphic VT with prolonged QT interval) and Digitalis-induced arrhythmias.

C. Atropine Sulfate (M-Cholinoblocker)

  • Mechanism: Competitively blocks vagal M2 muscarinic receptors in the SA and AV nodes, removing inhibitory parasympathetic tone.
  • Indications: Symptomatic sinus bradycardia, vasovagal syncope, and AV nodal conduction blocks (0.5-1.0 mg IV).
Coronary PDF 1 Questions 10 - 12 (Nitrates, Beta-blockers, CCBs, Trimetazidine, Pre/Postload)

Module 3: Antianginal Drugs & Myocardial Ischemia

1. Myocardial Oxygen Supply vs. Demand Balance

Angina pectoris results from an imbalance between myocardial oxygen demand (MVO2) and coronary blood flow (oxygen supply). MVO2 is determined by Heart Rate, Myocardial Contractility, and Ventricular Wall Tension (Wall tension = Pressure x Radius / 2 x Wall Thickness, governed by Preload and Afterload).

2. Classification of Antianginal Drugs

Group Representative Drugs Predominant Hemodynamic Action Effect on O2 Demand vs Supply Key Adverse Reactions
Organic Nitrates Nitroglycerin, ISDN, ISMN Potent venodilation (preload ⬇⬇); higher doses dilate large coronary collaterals & arterioles (afterload ⬇) Decreases MVO2 by reducing ventricular volume; improves subendocardial perfusion Throbbing headache, postural hypotension, reflex tachycardia, tolerance
Beta-Adrenoblockers Bisoprolol, Metoprolol, Atenolol Decreases heart rate, contractility, and systolic BP Markedly decreases MVO2; lengthens diastole to increase coronary perfusion time Bradycardia, fatigue, bronchospasm (in asthma), cold extremities, rebound ischemia
Calcium Channel Blockers (DHP) Amlodipine, Nifedipine, Lercanidipine Potent arteriolar and coronary vasodilation (afterload ⬇⬇) Decreases afterload; relieves coronary vasospasm Reflex tachycardia, peripheral pretibial edema, headache, flushing
Calcium Channel Blockers (Non-DHP) Verapamil, Diltiazem Direct negative inotrope, negative chronotrope, and negative dromotrope Decreases MVO2 via reduced HR and contractility; relieves spasm Bradycardia, AV block, constipation (verapamil), worsening HF
Metabolic Agents Trimetazidine, Ranolazine Shifts fatty acid oxidation to glucose oxidation / inhibits late Na+ current Improves cardiac cellular efficiency without any hemodynamic or BP changes! Extrapyramidal tremor (trimetazidine), nausea
If Channel Inhibitors Ivabradine Selectively blocks funny current (If) in sinus node Pure heart rate reduction without affecting BP, contractility, or AV conduction Phosphenes (visual luminous phenomena), bradycardia
⚡ Mechanism of Organic Nitrates & Molsidomine:

Nitrates enter vascular smooth muscle and are metabolized by mitochondrial aldehyde dehydrogenase (ALDH-2) to release Nitric Oxide (NO). NO activates soluble guanylyl cyclase -> increases cyclic GMP (cGMP) -> activates protein kinase G -> dephosphorylates myosin light chain -> vascular smooth muscle relaxation. Venodilation dominates at therapeutic doses, lowering central venous return (preload) and ventricular wall stress.

  • Nitrate Tolerance (Tachyphylaxis): Continuous exposure depletes tissue sulfhydryl (-SH) groups and causes neurohormonal counter-regulation. Prophylaxis: Provide an eccentric dosing schedule with a daily nitrate-free interval of 8-12 hours (e.g., take at 8 AM and 2 PM, none at night for stable angina).
  • Molsidomine (Sydnonimine derivative): Bioactivated non-enzymatically in the liver to linsidomine (SIN-1), directly releasing NO without requiring ALDH-2 or sulfhydryl groups. Hence, tolerance develops much slower than with classic nitrates!
⚠️ LETHAL DRUG INTERACTION: NITRATES + PDE-5 INHIBITORS

Combining nitrates with PDE-5 inhibitors (Sildenafil / Viagra within 24 hours, Tadalafil / Cialis within 48 hours) prevents the breakdown of cGMP. The resulting massive synergy of cGMP causes catastrophic, refractory vasodilation, life-threatening hypotension, myocardial infarction, and death! This is an absolute contraindication tested on every pharmacology exam.

3. Selection Tactics in Associated Pathologies

  • Angina + Hypertension: Beta-blocker + DHP CCB (Amlodipine) or ACE inhibitor.
  • Vasospastic (Prinzmetal / Variant) Angina: Calcium channel blockers (DHP or Diltiazem) + Nitrates are drugs of choice. Beta-blockers are CONTRAINDICATED because blocking beta-2 vasodilation leaves alpha-1 vasoconstriction unopposed, triggering severe coronary spasm!
  • Angina + Chronic Heart Failure: Beta-blockers (Bisoprolol/Carvedilol) + Nitrates (ISDN). Avoid Verapamil/Diltiazem.
  • Angina + COPD / Asthma: Cardioselective Beta-1 blocker (Bisoprolol) at low titrated dose OR Calcium Channel Blocker (Amlodipine) OR Ivabradine / Trimetazidine. Avoid non-selective beta-blockers!

4. The Coronary Steal Phenomenon

Non-selective, potent arteriolar coronarodilators such as Dipyridamole dilate resistance arterioles in normal, non-ischemic myocardial zones. Arterioles in the ischemic zone are already maximally dilated by endogenous metabolites (adenosine, acidosis). Consequently, blood flow is diverted away from the ischemic zone toward the non-ischemic zone—worsening myocardial ischemia. This is the 'coronary steal phenomenon'.

Hemostasis PDF 1 Questions 13 - 24 (Anticoagulants, Antiplatelets, Fibrinolytics, Coagulants, Antidotes)

Module 4: Hemostatic, Antithrombotic & Fibrinolytic Drugs

1. Master Classification of Drugs Influencing Hemostasis

A. ANTITHROMBOTIC DRUGS (Prevent/Dissolve Clots)

  • Anticoagulants:
    • Direct (Parenteral): UFH, LMWH (Enoxaparin, Nadroparin), Fondaparinux, Bivalirudin, Argatroban.
    • Direct (Oral - DOACs): Rivaroxaban, Apixaban (Factor Xa inhibitors); Dabigatran (Thrombin inhibitor).
    • Indirect (Oral - VKAs): Warfarin, Acenocoumarol.
  • Antiplatelet Agents (Antiaggregants): Aspirin (COX-1), Clopidogrel, Ticagrelor (P2Y12), Tirofiban, Abciximab (GPIIb/IIIa).
  • Fibrinolytics (Thrombolytics): Alteplase (rt-PA), Tenecteplase, Streptokinase.

B. HEMOSTATIC DRUGS (Stop Bleeding)

  • Coagulants:
    • Systemic: Vitamin K1 (Phytomenadione), Factor VIII/IX concentrates, Prothrombin Complex Concentrate (PCC), Fibrinogen.
    • Local: Thrombin powder, Hemostatic gelatin sponge, Fibrin glue, Epinephrine gauze.
  • Antifibrinolytics: Aminocaproic acid (EACA), Tranexamic acid (TXA), Aprotinin.
  • Capillary Angioprotectors & Aggregants: Etamsylate (Dicynone), Calcium dobesilate, Troxerutin.

2. Direct Anticoagulants: UFH vs. LMWH (Comparative Analysis)

Property Unfractionated Heparin (UFH) Low Molecular Weight Heparins (LMWH - Enoxaparin)
Molecular Weight 12,000 - 15,000 Da (heterogeneous) 4,000 - 5,000 Da (depolymerized fragments)
Mechanism of Action Binds Antithrombin III -> 1000-fold accelerates inhibition of Thrombin (IIa) and Factor Xa in equal 1:1 ratio Binds ATIII -> conformational change that predominantly inhibits Factor Xa (Anti-Xa to Anti-IIa ratio 3:1 to 4:1)
Route & Bioavailability IV or SC; low bioavailability (~30% SC) due to binding to plasma proteins and endothelium SC; high bioavailability (>90% SC) with predictable dose-response
Half-life (t1/2) Short (1 - 2 hours); rapid clearance Long (4 - 7 hours); permits once or twice daily dosing
Laboratory Monitoring Mandatory monitoring with aPTT (target 1.5 - 2.5 times control) No routine monitoring required (Anti-Factor Xa assay only in severe renal failure, obesity, pregnancy)
Elimination Reticuloendothelial system and liver; safer in renal failure Purely renal elimination; requires 50% dose reduction if CrCl < 30 mL/min
HIT Risk (Type II) Higher risk (1 - 5%) Significantly lower risk (< 1%)
Specific Antidote Protamine sulfate (1 mg neutralizes ~100 IU UFH; 100% complete neutralization) Protamine sulfate (only partially neutralizes anti-Xa activity, ~60%)

3. Indirect Anticoagulants (Vitamin K Antagonists: Warfarin & Acenocoumarol)

  • Mechanism: Competitively inhibits Vitamin K Epoxide Reductase Complex 1 (VKORC1) -> blocks the regeneration of reduced Vitamin K (hydroquinone) -> inhibits the hepatic post-translational gamma-carboxylation of glutamic acid residues on Factors II, VII, IX, X and anticoagulant Proteins C and S.
  • Latency of Action: Has NO effect on already circulating clotting factors. Full antithrombotic effect is delayed by 36 to 72 hours until pre-existing factors are cleared (Factor VII t1/2 ~6h, Factor II t1/2 ~60h).
  • Transient Hypercoagulability Trap: Protein C has a very short half-life (~8h) and is depleted before prothrombin (II). This causes a temporary prothrombotic state. Therefore, Warfarin MUST ALWAYS be bridged with Heparin/LMWH for at least 5 days and until INR is in the therapeutic range for 2 consecutive days, to prevent warfarin-induced skin necrosis!
  • Laboratory Monitoring: Monitored using Prothrombin Time (PT) expressed as International Normalized Ratio (INR). Target INR: 2.0 - 3.0 (for DVT/PE, AFib) or 2.5 - 3.5 (for mechanical prosthetic heart valves).
  • Antidotes:
    • For asymptomatic INR elevation: Withhold dose ± oral Vitamin K1 (Phytomenadione 1-5 mg).
    • For life-threatening major bleeding: 4-Factor Prothrombin Complex Concentrate (PCC 25-50 IU/kg IV) for immediate factor replacement + IV Vitamin K1 (10 mg slow infusion) to stimulate sustained endogenous factor synthesis.
  • Teratogenicity: Warfarin readily crosses the placenta and is strictly contraindicated during pregnancy (causes Fetal Warfarin Syndrome: chondrodysplasia punctata, microcephaly, optic atrophy, fetal hemorrhage). Heparins do NOT cross the placenta and are safe!

4. Antiplatelet Drugs (Antiaggregants)

Aspirin (Acetylsalicylic Acid)

  • Mechanism: Irreversibly acetylates and inactivates platelet cyclooxygenase-1 (COX-1), blocking conversion of arachidonic acid into Thromboxane A2 (TXA2) for the entire 7-10 day lifespan of the anucleate platelet.
  • Dosing Principle: Low doses (75 - 100 mg/day) selectively inhibit platelet TXA2 while sparing vascular endothelial COX-2 synthesis of prostacyclin (PGI2, an antiaggregant and vasodilator).

P2Y12 ADP Antagonists (Clopidogrel, Ticagrelor)

  • Clopidogrel: Thienopyridine prodrug; requires hepatic two-step bioactivation by CYP2C19 to form an active metabolite that irreversibly blocks P2Y12 receptors. Omeprazole inhibits CYP2C19 and reduces efficacy!
  • Ticagrelor: Direct-acting, reversible cyclopentyltriazolopyrimidine P2Y12 antagonist; does not require metabolic activation. Faster onset and more potent.

5. Fibrinolytics (Thrombolytics) vs. Antifibrinolytics

Fibrinolytics (Alteplase / rt-PA)

  • Mechanism: Fibrin-specific recombinant tissue plasminogen activator. Binds to fibrin within the thrombus and converts trapped plasminogen to active plasmin, which cleaves the fibrin meshwork.
  • Indications: Acute STEMI within 12h (if PCI not available <120 min), Acute ischemic stroke within 4.5h, Massive PE with hemodynamic collapse.
  • Absolute Contraindications: Prior intracranial hemorrhage, ischemic stroke within 6 months, known cerebral vascular malformation or neoplasm, major surgery/trauma within 3 weeks, active internal bleeding, suspected aortic dissection.

Antifibrinolytics (Aminocaproic & Tranexamic Acid)

  • Mechanism: Synthetic lysine analogs that competitively bind to the lysine-binding sites on plasminogen and plasmin, preventing their interaction with fibrin.
  • Indications: Antidote for fibrinolytic overdose (Alteplase/Streptokinase), hyperfibrinolysis, surgical bleeding (prostatectomy, cardiac surgery), menorrhagia, dental extraction in hemophiliacs.
  • Contraindications: DIC without heparin; hematuria from upper urinary tract (can cause fatal ureteral clot obstruction).
Hypertension PDF 2 Questions 1 - 11 (Central, Ganglioplegics, Alpha/Beta-blockers, CCBs, RAAS, Vasodilators)

Module 5: Antihypertensive Pharmacology & Hypertensive Crises

1. Comprehensive Classification of Antihypertensive Drugs

  1. Centrally Acting Sympatholytics:
    • Alpha-2 Agonists: Methyldopa (drug of choice in pregnancy), Clonidine (alpha-2 and I1 agonist).
    • Selective Imidazoline I1-Receptor Agonists: Moxonidine, Rilmenidine (RVLM medulla action; lower sedation).
  2. Ganglioplegics & Peripheral Sympatholytics:
    • Ganglion Blockers (Nn blockers): Hexamethonium, Trepirium, Trimethaphan (historical; controlled hypotension).
    • Adrenergic Neuron Blockers: Reserpine (depletes vesicular monoamines; depression/ulcer risk), Guanethidine.
  3. Adrenoblockers:
    • Selective Alpha-1 Blockers: Prazosin, Doxazosin, Terazosin, Urapidil. Indicated in HTA + BPH. Risk: First-dose orthostatic syncope.
    • Non-selective Alpha-1/Alpha-2 Blockers: Phentolamine, Phenoxybenzamine (used in Pheochromocytoma).
    • Beta-Blockers: Cardioselective (Metoprolol, Bisoprolol, Nebivolol), Non-selective (Propranolol), Vasodilating (Carvedilol, Labetalol).
  4. Calcium Channel Blockers (CCBs):
    • Dihydropyridines (Vascular selective): Amlodipine, Nifedipine retard, Lercanidipine.
    • Non-Dihydropyridines (Cardioselective): Verapamil (phenylalkylamine), Diltiazem (benzothiazepine).
  5. Inhibitors of the Renin-Angiotensin-Aldosterone System (RAAS):
    • Direct Renin Inhibitors: Aliskiren.
    • ACE Inhibitors: Captopril, Enalapril, Lisinopril, Ramipril, Perindopril.
    • Angiotensin Receptor Blockers (ARBs): Losartan, Valsartan, Candesartan, Telmisartan.
    • Angiotensin Receptor-Neprilysin Inhibitor (ARNI): Sacubitril + Valsartan.
  6. Musculotropic Vasodilators:
    • Arteriodilators: Hydralazine, Minoxidil (opens K_ATP channels; hirsutism), Diazoxide.
    • Venodilators: Nitroglycerin, Isosorbide dinitrate.
    • Arterio-Venodilators: Sodium Nitroprusside (rapid NO release; cyanide risk).
  7. Diuretics: Thiazide-like (Indapamide, Chlorthalidone), Loop (Furosemide), MRAs (Spironolactone).

2. Clinical Pharmacology of Beta-Adrenoblockers

Antihypertensive Mechanisms:

  • Inhibition of cardiac Beta-1 receptors -> decreases heart rate and myocardial contractility -> decreases Cardiac Output.
  • Inhibition of juxtaglomerular Beta-1 receptors -> suppresses Renin release -> suppresses RAAS axis.
  • Central nervous system reduction of sympathetic outflow.
  • Long-term resetting of baroreceptor sensitivity.
  • Vasodilating beta-blockers: Nebivolol (endothelial NO release), Carvedilol/Labetalol (Alpha-1 blockade).

Adverse Reactions & Contraindications:

  • Sinus bradycardia, high-grade AV block, acute decompensated heart failure.
  • Bronchospasm: Beta-2 blockade triggers life-threatening bronchoconstriction in asthma/severe COPD.
  • Peripheral Vasoconstriction: Unopposed alpha-1 tone causes cold extremities and worsens Raynaud's phenomenon.
  • Masking Hypoglycemia: Blunts tachycardia and tremor during insulin-induced hypoglycemia (sweating is preserved).
  • Abrupt Withdrawal Syndrome: Upregulated receptors cause rebound severe hypertension, tachycardia, and MI. Must taper over 1-2 weeks!

3. Calcium Channel Blockers: DHPs vs. Non-DHPs

Feature Dihydropyridines (Amlodipine, Lercanidipine) Non-Dihydropyridines (Verapamil, Diltiazem)
Primary Selectivity Vascular smooth muscle L-type Ca2+ channels (Arteriodilation) Myocardial and nodal L-type Ca2+ channels (Heart > Vessels)
Cardiac Effects No direct negative inotropic/dromotropic effect; can cause reflex tachycardia Decreases contractility (negative inotrope) and slows AV conduction (negative dromotrope)
Characteristic Adverse Effects Pretibial ankle edema (precapillary arteriolar dilation), facial flushing, headache Bradycardia, AV conduction block, constipation (verapamil in 30%), worsening systolic HF
Compelling Indications Isolated systolic HTA in elderly, Angina, Raynaud's, Pregnancy (Nifedipine) HTA with tachycardia, AFib rate control, Paroxysmal SVT
Dangerous Interaction Safe to combine with Beta-blockers (counteracts reflex tachycardia) NEVER combine IV Verapamil with IV Beta-blocker (triggers fatal asystole / arrest)!

4. RAAS Inhibitors: ACE Inhibitors vs. ARBs

ACE Inhibitors (Captopril, Enalapril, Lisinopril)

  • Inhibits ACE (kininase II) -> decreases Angiotensin II and aldosterone; simultaneously prevents the degradation of Bradykinin and Substance P.
  • Accumulation of bradykinin in lung tissue causes persistent dry cough (10-20%) and angioedema (0.5%, life-threatening).
  • Gold standard for diabetic nephropathy: selectively dilates efferent arteriole, reducing intraglomerular pressure and proteinuria.

ARBs / Sartans (Losartan, Valsartan)

  • Selectively and competitively block the AT1 receptor subtype, preventing Ang II from exerting its vasoconstrictive and remodeling actions.
  • Does NOT block ACE; does NOT increase bradykinin levels. Hence, virtually zero incidence of dry cough!
  • First-line alternative when patients develop intolerable ACE inhibitor cough.
  • Losartan uniquely inhibits renal URAT1, exerting a uricosuric effect (lowers serum uric acid, ideal in gout!).

5. Hypertensive Emergencies vs. Urgencies Protocol

Hypertensive Emergency: Severe BP elevation (>180/120 mmHg) accompanied by acute progressive target organ damage (encephalopathy, acute aortic dissection, acute pulmonary edema, acute MI, eclampsia). Requires immediate IV therapy in ICU, lowering MAP by 20-25% over the first hour.

  • Aortic Dissection: Target SBP < 120 mmHg and HR < 60 bpm within 20 min. IV Beta-blocker (Esmolol or Labetalol) MUST BE GIVEN FIRST before vasodilators to prevent reflex tachycardia and aortic shear stress rupture!
  • Acute Pulmonary Edema: IV Nitroglycerin or Nitroprusside + IV Furosemide. Avoid beta-blockers!
  • Eclampsia / Severe Pre-eclampsia: IV Magnesium Sulfate (anti-seizure) + IV Labetalol or IV Hydralazine.
Renal PDF 2 Question 12 (Loop, Thiazides, K-sparing, Osmotics, CA inhibitors, Ion excretion)

Module 6: Diuretic Pharmacology & Ion Balance Regulation

1. Classification of Diuretics by Potency & Site of Action

Group Nephron Segment Molecular Target Natriuretic Potency (% Filtered Na+ Excreted) Representative Drugs Onset (Latency) & Duration
High-Ceiling / Loop Diuretics Thick Ascending Limb (TAL) of Henle Inhibits luminal NKCC2 (Na+/K+/2Cl- cotransporter) High (20 - 25%) Furosemide, Torsemide, Bumetanide IV: 5 min, lasts 2h. Oral: 30-60 min, lasts 4-6h ('Furious-semide')
Thiazide & Thiazide-like Early Distal Convoluted Tubule (DCT) Inhibits luminal NCC (Na+/Cl- cotransporter) Moderate (5 - 10%) Hydrochlorothiazide, Indapamide, Chlorthalidone Oral: 1-2 hours, lasts 12-24h (HCTZ) up to 48-72h (Chlorthalidone)
Competitive Aldosterone Antagonists (MRA) Cortical Collecting Duct (CCD) Blocks intracellular Mineralocorticoid Receptor Low / Mild (2 - 3%) Spironolactone, Eplerenone Slow (24-48 hours latency; requires genomic action), lasts 2-3 days
Non-Competitive Aldosterone Antagonists Cortical Collecting Duct (CCD) Directly blocks apical ENaC (Epithelial Na+ Channel) Low / Mild (2 - 3%) Amiloride, Triamterene Oral: 2 hours, lasts 12-24 hours
Carbonic Anhydrase Inhibitors (CAI) Proximal Convoluted Tubule (PCT) Inhibits membrane & cytoplasmic Carbonic Anhydrase Low (3 - 5%) Acetazolamide Oral: 1-2 hours, lasts 8-12 hours
Osmotic Diuretics PCT & Thin Descending Limb of Henle Creates non-reabsorbable intraluminal osmotic gradient Variable / Water diuresis Mannitol (IV) IV: 15-30 min, lasts 3-6 hours

2. Master Ion Excretion & Metabolic Effect Matrix

Diuretic Class Na+ & Cl- K+ Mg2+ Ca2+ Acid-Base Balance Uric Acid & Glucose
Loop Diuretics (Furosemide) ⬆⬆⬆ ⬆⬆ (Wasted) ⬆⬆ (Wasted) ⬆⬆ (WASTED! Loops Lose Calcium) Hypokalemic Metabolic Alkalosis Hyperuricemia (gout risk), mild Hyperglycemia
Thiazides (Indapamide / HCTZ) ⬆⬆ ⬆ (Wasted) ⬆ (Wasted) ⬇⬇ (REABSORBED! Thiazides Save Calcium) Hypokalemic Metabolic Alkalosis Hyperuricemia, Hyperglycemia (inhibits insulin release), Hyperlipidemia
K+-Sparing (Spironolactone / Amiloride) ⬆ (Mild) ⬇⬇ (RETAINED! Spares Potassium) Neutral/⬇ Neutral Hyperkalemic Metabolic Acidosis Neutral
CAI (Acetazolamide) ⬆ ⬆ (Wasted) Neutral Neutral Hyperchloremic Metabolic Acidosis (HCO3- wasting) Neutral
⚡ High-Yield Clinical Pearls for Diuretics:
  • Why do Loops lose Calcium while Thiazides save Calcium? In the thick ascending limb, NKCC2 activity creates a lumen-positive transepithelial potential (+10 mV) that drives paracellular reabsorption of Ca2+ and Mg2+. Loop diuretics abolish this positive potential, causing massive renal wasting of Ca2+ and Mg2+ (useful to treat severe Hypercalcemia!). In the DCT, thiazides block Na+ entry, which stimulates the basolateral 3Na+/1Ca2+ exchanger, pulling more Ca2+ from urine back into blood (useful in Recurrent Calcium Nephrolithiasis and Osteoporosis!).
  • Indapamide's Unique Profile: Unlike other thiazides, Indapamide causes minimal metabolic derangements (neutral on glucose and lipids) and has additional direct arterial vasodilatory actions. It remains effective even when GFR falls to 30 mL/min!
  • Ototoxicity: Loop diuretics can cause dose-dependent, reversible or permanent sensorineural hearing loss and tinnitus (especially with rapid IV boluses or when combined with aminoglycoside antibiotics).
Critical Care PDF 2 Questions 13 - 22 (Adrenomimetics, Dopamine, Difetur, Analeptics, Permissive Hormones, Volume Expanders)

Module 7: Antihypotensive Pharmacology & Shock Resuscitation

1. Comprehensive Classification of Antihypotensive Drugs

  1. Adrenomimetics & Vasopressors:
    • Alpha-Beta Adrenomimetics: Epinephrine (Adrenaline), Norepinephrine (Noradrenaline), Ephedrine.
    • Selective Alpha-1 Adrenomimetics: Phenylephrine (Mesaton), Midodrine (Gutron - oral prodrug).
    • Selective Beta-1 Adrenomimetics: Dobutamine (cardiostimulator / inotrope).
    • Dopaminomimetics: Dopamine (dose-dependent D1, Beta-1, Alpha-1).
  2. Isothioureic Derivatives: Difetur (acts on peripheral vascular receptors, elevates peripheral vascular resistance in collapse).
  3. Vasoactive Peptides: Angiotensin II (Giapreza), Vasopressin (Argipressin / ADH - V1a receptor agonist).
  4. Central Acting Analeptics & CNS Stimulants:
    • Caffeine Sodium Benzoate: Adenosine antagonist + PDE inhibitor; stimulates medullary vasomotor and respiratory centers.
    • Cordiamine (Nikethamide): Central and chemoreceptor analeptic.
    • Camphor / Sulfocamphocain: Analeptic, enhances venous tone and myocardial metabolism.
    • Herbal Adaptogens / Tonics: Ginseng, Eleutherococcus (used for chronic constitutional hypotension).
  5. Drugs with Permissive & Complex Action: Glucocorticoids (Hydrocortisone, Prednisolone, Dexamethasone). Upregulate downregulated vascular alpha-1 receptors and restore catecholamine sensitivity in refractory shock.
  6. Plasma Volume Expanders & Substitutes:
    • Crystalloids: 0.9% Normal Saline, Ringer's Lactate (expand interstitial and intravascular space).
    • Colloids: Dextrans (Dextran 40 - Rheopolyglucin, Dextran 70 - Polyglucin), Hydroxyethyl Starch (HES), Gelatin solutions (Gelofusine), Human Albumin (5%, 20%).

2. Comparative Hemodynamic Profiles of Vasoactive Adrenomimetics

Drug Receptor Selectivity Cardiac Output (CO) Systemic Vascular Resistance (SVR) Heart Rate (HR) Drug of Choice Indication
Norepinephrine Alpha-1 (+++), Alpha-2 (++), Beta-1 (++) Neutral / ⬆ ⬆⬆⬆ (Potent vasoconstriction) Neutral / Reflex ⬇ First-line vasopressor in Septic Shock & Vasoplegic Shock
Epinephrine Alpha-1 (+++), Beta-1 (+++), Beta-2 (+++) ⬆⬆⬆ ⬆ at high dose; ⬇ at low dose (Beta-2) ⬆⬆⬆ (Tachycardia) Drug of Choice in Anaphylactic Shock & Cardiac Arrest (ACLS)
Phenylephrine Alpha-1 (Pure +++) Neutral / ⬇ ⬆⬆⬆ ⬇ (Marked reflex bradycardia) Anesthesia-induced hypotension; SVT termination
Dobutamine Beta-1 (+++), Beta-2 (+), Alpha-1 (minimal) ⬆⬆⬆ (Potent Inotrope) ⬇ (Mild vasodilation) ⬆ (Mild-to-moderate) First-line inotrope in Cardiogenic Shock with adequate BP
Dopamine D1 (low dose) -> Beta-1 (mid) -> Alpha-1 (high) ⬆⬆ ⬇ (low dose) -> ⬆⬆ (high dose) ⬆⬆ (High arrhythmia risk) Cardiogenic shock with bradycardia; second-line

3. Clinical Principles in Different Types of Arterial Hypotension

  • Hypotonic Arterial Hypotension (Vasomotor Collapse / Septic / Anaphylactic): SVR is pathologically low due to widespread vasodilation. Management: Rapid fluid resuscitation (crystalloids 30 ml/kg) + Norepinephrine infusion to restore vascular resistance. For anaphylaxis: immediate IM Epinephrine (0.3-0.5 mg).
  • Hypertonic Arterial Hypotension (Cardiac / Acute MI Pump Failure): Left ventricular failure causes low cardiac output, which triggers intense compensatory neurohormonal vasoconstriction (high SVR). Management: Positive inotropes (Dobutamine, Levosimendan) to restore stroke volume; avoid pure vasoconstrictors (Phenylephrine) which would cause fatal afterload mismatch!
  • Hypovolemic Arterial Hypotension (Hemorrhage, Severe Dehydration): Low intravascular volume and low venous return. Management: Crystalloids, colloids, and packed red blood cells. Vasopressors are only used temporarily if fluids fail to maintain perfusion.
  • Orthostatic (Postural) Hypotension: Blood pooling in lower extremities upon standing. Management: Non-pharmacological (elastic compression stockings, increased water/salt) + Midodrine (selective oral alpha-1 agonist prodrug) or Fludrocortisone (mineralocorticoid plasma expander).

4. Special Populations: Pregnancy, Pediatrics, Geriatrics

Pharmacotherapy in Pregnancy:

  • Antihypertensives of Choice: Methyldopa (decades of proven fetal safety), Labetalol (combined alpha/beta-blocker), Nifedipine retard, and Hydralazine (for emergency IV use).
  • Strictly Contraindicated in Pregnancy: ACE inhibitors and ARBs (cause fetal renal agenesis, oligohydramnios, skull hypoplasia), Direct Renin Inhibitors, Sodium Nitroprusside (fetal cyanide poisoning), and Diuretics (hypoperfusion of placenta).
  • Anticoagulation in Pregnancy: LMWH (Enoxaparin) and UFH do NOT cross the placenta and are safe throughout pregnancy. Warfarin is teratogenic (Fetal Warfarin Syndrome) and strictly contraindicated, especially in the 1st trimester.

📸 Official Faculty Textbook Dose-Response Tree (Page 228 Reference):

Official Curriculum Reference • Page 228

Dose-Dependent Hemodynamic Effects of Dopamine

Remedies acting on the peripheral autonomic nervous system • Pharmacodynamic dose titration

Small Doses (Low Dose) 0.5 - 2 mcg/kg/min

Dopaminergic Receptor (D1) Phase

Excitation of vascular dopamine D1 receptors predominates:

  1. Positive inotropic effect WITHOUT tachycardia
  2. Selective renal and mesenteric vasodilation
  3. Improvement of systemic and organ hemodynamics
  4. Increased diuresis and natriuresis (renal protective flow)
  5. Correction of arterial hypotension of hypertonic/cardiac type (preserves renal perfusion)
  6. High clinical efficacy in acute heart failure
Medium Doses (Intermediate) 2 - 10 mcg/kg/min

Beta-1 Adrenergic Phase (The 4 Positive Tropisms)

Excitation of myocardial Beta-1 adrenoreceptors predominates:

  1. Positive inotropic effect (+): increases force of contraction & stroke volume
  2. Positive chronotropic effect (+): accelerates heart rate (tachycardia begins)
  3. Positive dromotropic effect (+): speeds AV nodal conduction velocity
  4. Positive bathmotropic effect (+): enhances myocardial excitability
  5. High efficacy in acute heart failure & cardiogenic shock
Large Doses (High Dose) > 10 mcg/kg/min

Alpha-Adrenergic Vasopressor Phase

Excitation of vascular Alpha-1 & Alpha-2 receptors predominates:

  1. Intense generalized arterio- and venoconstriction
  2. Marked increase in systemic vascular resistance (SVR) and arterial blood pressure
  3. Reduction of peripheral microcirculation with risk of tissue hypoxia, ischemia, acidosis, and necrosis
  4. Oligo- or anuria (due to severe renal vasoconstriction)
  5. Efficacy in hypotonic or mixed-type arterial hypotension (vasomotor collapse, septic shock)

🎯 Sequence 1.1: Clinical Scenarios & Personal Drug (P-Drug) Selection

Complete coverage of all 50 clinical pathologies from Section F.1.1 of both methodological guidelines. Filter by specialty or search in real-time.

Acute heart failure (ADHF) / Heart failure with pulmonary edema Heart Failure
💊 Drug of Choice (P-Drug): Furosemide (IV 40-80 mg bolus) + Nitroglycerin (IV infusion 10-200 mcg/min) + Oxygen (± CPAP/BiPAP)
🔄 Alternative Agents: Morphine IV (1-3 mg slow, for anxiety/dyspnea), Dobutamine IV (if low BP / cardiogenic component), Levosimendan IV
⚡ Mechanism of Action & Rationale: Loop diuretic causes rapid venodilation (within 5-15 min via prostaglandins) followed by diuresis, reducing preload. Nitrates reduce both preload and afterload. Inotropes increase contractility if hypoperfusion exists.
⚠️ Common Exam Trap & What to AVOID: AVOID Beta-blockers in acute decompensated pulmonary edema (can precipitate acute cardiogenic shock)! AVOID excessive fluids or negative inotropes (Verapamil/Diltiazem).
Chronic heart failure, NYHA class I and II Heart Failure
💊 Drug of Choice (P-Drug): ACE inhibitor (Enalapril 2.5-10 mg BID or Ramipril 2.5-10 mg daily) OR ARNI (Sacubitril/Valsartan 49/51 mg BID) + Beta-blocker (Bisoprolol 1.25-10 mg daily or Carvedilol)
🔄 Alternative Agents: ARB (Losartan 50 mg daily or Candesartan 4-32 mg daily), SGLT2 inhibitor (Dapagliflozin 10 mg daily)
⚡ Mechanism of Action & Rationale: Inhibits RAAS remodeling, reduces afterload/preload, prevents neurohormonal catecholamine-induced cardiomyocyte apoptosis, lowers mortality and hospitalization.
⚠️ Common Exam Trap & What to AVOID: Do NOT start beta-blockers at high doses; start low ('start low, go slow'). Do NOT combine ACEi + ARB + Direct Renin Inhibitor (hyperkalemia & acute renal failure risk).
Chronic heart failure, NYHA class III and IV Heart Failure
💊 Drug of Choice (P-Drug): Quadruple Therapy (GDMT): ARNI (Sacubitril/Valsartan) + Beta-blocker (Bisoprolol/Carvedilol) + MRA (Spironolactone 25-50 mg daily) + SGLT2i (Empagliflozin/Dapagliflozin) + Loop Diuretic (Furosemide 40-80 mg daily for congestion)
🔄 Alternative Agents: Digoxin 0.125-0.25 mg daily (for symptomatic relief / rate control if AFib), Hydralazine + Isosorbide Dinitrate
⚡ Mechanism of Action & Rationale: Comprehensive neurohormonal blockade + congestion control. Aldosterone receptor antagonism prevents progressive myocardial fibrosis and decreases mortality.
⚠️ Common Exam Trap & What to AVOID: Monitor Potassium and Serum Creatinine closely! If K+ > 5.5 mmol/L or GFR < 30 ml/min, cautiously adjust MRA. Avoid NSAIDs (worsen fluid retention and renal function).
Heart failure with hyperaldosteronism (secondary) Heart Failure
💊 Drug of Choice (P-Drug): Spironolactone (25-100 mg daily orally) or Eplerenone (25-50 mg daily)
🔄 Alternative Agents: Amiloride or Triamterene (non-competitive ENaC blockers)
⚡ Mechanism of Action & Rationale: Competitively blocks mineralocorticoid receptors in late distal tubule and collecting ducts; prevents sodium retention, potassium wasting, and myocardial/vascular interstitial fibrosis.
⚠️ Common Exam Trap & What to AVOID: Hyperkalemia risk, especially if combined with ACE inhibitors or potassium supplements. Spironolactone can cause painful gynecomastia and menstrual irregularities (antiandrogenic); switch to Eplerenone if this occurs.
Cardiotonic glycoside intoxication (Digoxin poisoning) Heart Failure
💊 Drug of Choice (P-Drug): Digoxin-specific Fab antibody fragments (Digibind / DigiFab) for life-threatening toxicity + Potassium chloride IV/oral (if hypokalemic and normal AV conduction)
🔄 Alternative Agents: Magnesium sulfate IV (1-2 g for arrhythmias), Lidocaine IV or Phenytoin IV (for ventricular tachyarrhythmias), Atropine IV (0.5-1.0 mg for severe bradycardia/AV block)
⚡ Mechanism of Action & Rationale: Fab fragments bind free digoxin with high affinity and inactivate it. Potassium competes with digitalis for binding on myocardial Na+/K+-ATPase. Lidocaine suppresses digitalis-induced triggered automaticity without depressing AV conduction.
⚠️ Common Exam Trap & What to AVOID: NEVER give Calcium IV (causes 'stone heart' / irreversible contracture)! Avoid electrical DC cardioversion if possible (can trigger intractable ventricular fibrillation).
Arrhythmias due to cardiac glycoside intoxication Heart Failure
💊 Drug of Choice (P-Drug): Lidocaine (IV bolus 1-1.5 mg/kg, then infusion 1-4 mg/min) OR Phenytoin (IV 100 mg every 5 min up to 1000 mg)
🔄 Alternative Agents: Magnesium sulfate IV (2 g IV over 10 min), Atropine IV (for bradycardia/AV block)
⚡ Mechanism of Action & Rationale: Class IB antiarrhythmics suppress digitalis-induced delayed afterdepolarizations (DADs) and abnormal ventricular automaticity without worsening AV nodal conduction.
⚠️ Common Exam Trap & What to AVOID: Avoid Class IA (Quinidine, Procainamide) and Class IC (Flecainide) antiarrhythmics—they worsen conduction blocks and Quinidine displaces digoxin from tissue binding, doubling serum levels!
Paroxysmal supraventricular tachycardia (PSVT / AVNRT / AVRT) Arrhythmias
💊 Drug of Choice (P-Drug): Vagal maneuvers (Valsalva) -> IV Adenosine (6 mg rapid bolus into large vein followed by rapid flush, then 12 mg if no response)
🔄 Alternative Agents: Verapamil IV (5-10 mg slow) or Diltiazem IV; Beta-blocker (Esmolol IV / Metoprolol IV); Synchronized DC cardioversion if hemodynamically unstable
⚡ Mechanism of Action & Rationale: Adenosine stimulates A1 receptors in the AV node, activating inward K+ current and inhibiting adenylate cyclase/L-type Ca2+ current, causing profound transient AV nodal block (~10-15s) and interrupting reentry circuit.
⚠️ Common Exam Trap & What to AVOID: Contraindicated in 2nd/3rd degree AV block, sick sinus syndrome, or bronchospastic lung disease (asthma). Antagonized by methylxanthines (caffeine, theophylline).
Chronic atrial fibrillation, tachysystolic form (Rate Control) Arrhythmias
💊 Drug of Choice (P-Drug): Beta-adrenoblocker (Bisoprolol 2.5-10 mg daily or Metoprolol succinate 50-100 mg daily) OR Non-DHP CCB (Verapamil 80-240 mg or Diltiazem 120-360 mg) + Anticoagulation (DOAC / Warfarin)
🔄 Alternative Agents: Digoxin (0.125-0.25 mg daily - preferred if associated with systolic Heart Failure), Amiodarone (if other agents fail or unstable)
⚡ Mechanism of Action & Rationale: Slows AV nodal conduction velocity and prolongs refractory period, limiting the number of atrial impulses conducted to ventricles, controlling ventricular rate (<100-110 bpm).
⚠️ Common Exam Trap & What to AVOID: Avoid Verapamil/Diltiazem in Heart Failure with Reduced Ejection Fraction (HFrEF) due to negative inotropy. Never use AV nodal blockers alone in WPW with AFib (accelerates conduction over accessory bypass tract -> VF)!
Atrial fibrillation in mitral valve disease or prosthetic mechanical valves Arrhythmias
💊 Drug of Choice (P-Drug): Warfarin (target INR 2.5-3.5 for mechanical valves, 2.0-3.0 for mitral stenosis) + AV node rate control agent
🔄 Alternative Agents: Acenocoumarol (alternative Vitamin K antagonist), Phenprocoumon
⚡ Mechanism of Action & Rationale: VKORC1 inhibition reduces synthesis of factors II, VII, IX, X, preventing high shear-stress thrombogenesis on foreign prosthetic mechanical surfaces.
⚠️ Common Exam Trap & What to AVOID: DOACs (Rivaroxaban, Apixaban, Dabigatran) are CONTRAINDICATED in mechanical prosthetic heart valves (RE-ALIGN trial showed higher thromboembolism and bleeding)!
Atrial extrasystoles (premature atrial contractions) Arrhythmias
💊 Drug of Choice (P-Drug): Beta-adrenoblockers (Metoprolol 25-50 mg BID or Bisoprolol 2.5-5 mg daily)
🔄 Alternative Agents: Class IC (Propafenone 150 mg TID) or Class IV (Verapamil 40-80 mg TID)
⚡ Mechanism of Action & Rationale: Decreases Phase 4 sympathetic automaticity and membrane excitability in ectopic atrial foci.
⚠️ Common Exam Trap & What to AVOID: Reassure patient; treat underlying triggers (caffeine, smoking, stress, hyperthyroidism, electrolyte imbalance). Avoid Class IC if structural heart disease is present.
Paroxysms of ventricular tachycardia (VT) - Hemodynamically Stable Arrhythmias
💊 Drug of Choice (P-Drug): Amiodarone (IV 150-300 mg over 10-20 min, followed by continuous infusion 1 mg/min for 6h, then 0.5 mg/min) OR Lidocaine IV (1-1.5 mg/kg bolus)
🔄 Alternative Agents: Procainamide IV (20-50 mg/min until arrhythmia suppressed, max 17 mg/kg), Sotalol IV. If UNSTABLE: Synchronized DC cardioversion immediately!
⚡ Mechanism of Action & Rationale: Amiodarone prolongs action potential duration and effective refractory period (Class III K+ channel blockade) while exhibiting Class I, II, and IV antiarrhythmic properties.
⚠️ Common Exam Trap & What to AVOID: Avoid Verapamil or Adenosine if wide-complex tachycardia of uncertain origin—can trigger ventricular fibrillation and cardiac arrest!
Ventricular arrhythmias in patients with acute myocardial infarction Arrhythmias
💊 Drug of Choice (P-Drug): Lidocaine (IV 1-1.5 mg/kg bolus, then 2-4 mg/min maintenance) OR Amiodarone (IV 150-300 mg)
🔄 Alternative Agents: Beta-blocker IV (Metoprolol 5 mg slow IV if no contraindications/hypotension)
⚡ Mechanism of Action & Rationale: Class IB agent selectively binds and blocks open and inactivated voltage-gated Na+ channels in ischemic, depolarized ventricular myocardium, preventing reentrant VT/VF without depressing AV node or normal tissue.
⚠️ Common Exam Trap & What to AVOID: Class IC antiarrhythmics (Flecainide, Propafenone) are STRICTLY CONTRAINDICATED post-MI (CAST trial demonstrated marked increase in mortality and sudden cardiac death)!
Arrhythmias of sympathoadrenal origin (stress, pheochromocytoma, hyperthyroidism) Arrhythmias
💊 Drug of Choice (P-Drug): Non-selective or cardioselective Beta-blocker (Propranolol 20-40 mg TID, Metoprolol 25-50 mg BID, or Esmolol IV)
🔄 Alternative Agents: Carvedilol, Labetalol
⚡ Mechanism of Action & Rationale: Competitively blocks beta-1 adrenoreceptors, decreasing adenylyl cyclase activation, reducing cAMP and intracellular calcium, dampening sympathetic hyper-excitability and sinus/ectopic tachycardia.
⚠️ Common Exam Trap & What to AVOID: In pheochromocytoma, NEVER administer beta-blockers without prior effective alpha-blockade (Phentolamine/Phenoxybenzamine), otherwise severe unopposed alpha-1 vasoconstriction will trigger a fatal hypertensive crisis!
Atrioventricular (AV) block / Severe symptomatic bradycardia Arrhythmias
💊 Drug of Choice (P-Drug): Atropine sulfate (IV 0.5-1.0 mg, repeated every 3-5 min up to maximum 3 mg)
🔄 Alternative Agents: Isoproterenol (Isoprenaline) IV infusion (2-10 mcg/min), Epinephrine IV infusion (2-10 mcg/min), Temporary/Permanent Transcutaneous or Transvenous Pacemaker
⚡ Mechanism of Action & Rationale: Competitive M2 muscarinic acetylcholine receptor antagonist; removes parasympathetic/vagal inhibitory tone on SA node and AV node, accelerating sinus rate and AV nodal conduction velocity.
⚠️ Common Exam Trap & What to AVOID: Doses < 0.5 mg atropine can paradoxically cause central/presynaptic vagal bradycardia. Infranodal (Mobitz Type II or 3rd degree with wide QRS) AV blocks often do NOT respond to atropine and require immediate pacing.
Angina pectoris acute attack (relief of acute episode) Angina & IHD
💊 Drug of Choice (P-Drug): Sublingual Nitroglycerin (0.5 mg tablet dissolved under tongue or 1-2 sprays = 0.4-0.8 mg sublingually)
🔄 Alternative Agents: Isosorbide dinitrate sublingual (5 mg)
⚡ Mechanism of Action & Rationale: Rapidly generates nitric oxide (NO) -> activates soluble guanylyl cyclase -> increases cGMP -> dephosphorylates myosin light chain -> profound systemic venodilation (reduces venous return & ventricular preload) + epicardial coronary vasodilation.
⚠️ Common Exam Trap & What to AVOID: Contraindicated if patient took PDE-5 inhibitors (Sildenafil within 24h, Tadalafil within 48h) due to fatal refractory hypotension! Contraindicated in severe aortic stenosis, hypertrophic cardiomyopathy, and right ventricular infarction.
Prophylaxis of angina pectoris attacks / Chronic stable angina Angina & IHD
💊 Drug of Choice (P-Drug): Beta-blocker (Bisoprolol 5-10 mg daily or Metoprolol succinate 50-100 mg daily) + PRN sublingual Nitroglycerin
🔄 Alternative Agents: Dihydropyridine CCB (Amlodipine 5-10 mg daily), Long-acting nitrate (Isosorbide mononitrate 20-60 mg daily with eccentric dosing), Trimetazidine (35 mg BID), Ivabradine (5-7.5 mg BID)
⚡ Mechanism of Action & Rationale: Decreases heart rate, myocardial contractility, and systolic blood pressure, dramatically lowering myocardial oxygen demand (MVO2) and prolonging diastolic coronary perfusion time.
⚠️ Common Exam Trap & What to AVOID: Nitrate tolerance develops if given around-the-clock without an 8-12 hour daily nitrate-free interval. Do not abruptly stop beta-blockers (rebound angina, tachycardia, MI).
Vasospastic (Prinzmetal / Variant) angina pectoris Angina & IHD
💊 Drug of Choice (P-Drug): Calcium Channel Blockers (Dihydropyridine: Amlodipine 5-10 mg or Nifedipine retard 20-40 mg; OR Diltiazem 120-240 mg) + Nitrates
🔄 Alternative Agents: Nicorandil (10-20 mg BID)
⚡ Mechanism of Action & Rationale: Inhibits calcium influx via L-type channels in vascular smooth muscle, preventing and relieving coronary artery spasm and improving myocardial perfusion.
⚠️ Common Exam Trap & What to AVOID: Beta-blockers (especially non-selective like Propranolol) are STRICTLY CONTRAINDICATED in Prinzmetal angina! Blocking beta-2 vasodilation leaves alpha-1 receptors unopposed, precipitating severe coronary spasm and transmural infarction!
Unstable angina pectoris / Non-ST Elevation ACS (NSTE-ACS) Angina & IHD
💊 Drug of Choice (P-Drug): Dual Antiplatelet Therapy (DAPT: Aspirin 150-300 mg loading, then 75-100 mg + Ticagrelor 180 mg loading or Clopidogrel 300-600 mg) + Anticoagulation (Fondaparinux 2.5 mg SC or Enoxaparin 1 mg/kg BID) + Anti-ischemic therapy (Nitrates, Beta-blocker) + High-intensity Statin (Atorvastatin 80 mg)
🔄 Alternative Agents: Bivalirudin, Tirofiban IV (GPIIb/IIIa inhibitor in high-risk troponin-positive cases undergoing PCI)
⚡ Mechanism of Action & Rationale: Inhibits platelet aggregation, halts thrombus propagation on ruptured atherosclerotic plaque, reduces myocardial oxygen demand and plaque inflammation.
⚠️ Common Exam Trap & What to AVOID: Do NOT give fibrinolytics (tPA/Alteplase) in NSTE-ACS/unstable angina! Trials show no benefit and increased risk of bleeding and myocardial infarction.
Acute myocardial infarction (STEMI) - Emergency Management Angina & IHD
💊 Drug of Choice (P-Drug): 'MONA-BATS' protocol: Morphine IV (if severe chest pain), Oxygen (if SaO2 < 90%), Nitroglycerin SL/IV, Aspirin (300 mg chewed) + Ticagrelor/Prasugrel + Heparin/Enoxaparin + Beta-blocker (if no shock/HF) + Primary PCI (within 90-120 min)
🔄 Alternative Agents: Fibrinolysis (Alteplase IV 100 mg accelerated protocol or Tenecteplase) if PCI cannot be performed within 120 minutes of diagnosis
⚡ Mechanism of Action & Rationale: Immediate restoration of coronary artery patency, relief of ischemic pain, stabilization of coronary thrombus, reduction of infarct size and ventricular arrhythmias.
⚠️ Common Exam Trap & What to AVOID: Avoid Nitrates and Morphine in Right Ventricular Infarction (inferior STEMI with clear lungs and hypotension)—RV is preload dependent, nitrates cause profound circulatory collapse!
Acute myocardial infarction with hypercoagulability / Thromboembolic MI Angina & IHD
💊 Drug of Choice (P-Drug): Unfractionated Heparin (IV 60 IU/kg bolus, max 4000 IU; then 12 IU/kg/h) OR Enoxaparin (IV bolus 30 mg, followed by 1 mg/kg SC BID) + DAPT
🔄 Alternative Agents: Bivalirudin (direct thrombin inhibitor), Fondaparinux
⚡ Mechanism of Action & Rationale: Heparin potentiates antithrombin III, instantly neutralizing thrombin (Factor IIa) and Factor Xa, halting microvascular and intracoronary thromboembolism.
⚠️ Common Exam Trap & What to AVOID: Monitor aPTT (target 1.5-2.5x control) for UFH. Watch for Heparin-Induced Thrombocytopenia (HIT) around day 5-10.
Ischemic heart disease with associated arrhythmias Angina & IHD
💊 Drug of Choice (P-Drug): Beta-blocker (Metoprolol 50-100 mg daily or Bisoprolol 5-10 mg daily) OR Amiodarone (oral 200 mg daily maintenance)
🔄 Alternative Agents: Sotalol (Class III with beta-blocking activity)
⚡ Mechanism of Action & Rationale: Beta-blockers simultaneously decrease myocardial oxygen consumption (antianginal) and raise the ventricular fibrillation threshold while suppressing ectopic pacemaker activity (antiarrhythmic).
⚠️ Common Exam Trap & What to AVOID: Avoid Class IC agents (Flecainide/Propafenone) in IHD due to proarrhythmic risk (CAST trial). Avoid pure DHP CCBs without beta-blockers due to reflex tachycardia.
Ischemic heart disease with associated arterial hypertension Angina & IHD
💊 Drug of Choice (P-Drug): Beta-blocker (Bisoprolol / Metoprolol / Carvedilol) + ACE inhibitor (Enalapril / Ramipril / Lisinopril) ± DHP CCB (Amlodipine)
🔄 Alternative Agents: ARB (Losartan, Valsartan), Long-acting Dihydropyridine CCB
⚡ Mechanism of Action & Rationale: Beta-blockers lower blood pressure and oxygen consumption. ACE inhibitors reverse vascular remodeling, stabilize plaques, improve survival, and reduce afterload.
⚠️ Common Exam Trap & What to AVOID: Avoid short-acting Nifedipine without beta-blocker (causes sudden reflex tachycardia and increases ischemic events).
Ischemic heart disease in patients with obstructive pulmonary disease (COPD / Asthma) Angina & IHD
💊 Drug of Choice (P-Drug): Cardioselective Beta-1 blocker (Bisoprolol or Nebivolol or Metoprolol succinate) at low titrated dose OR Calcium Channel Blocker (Amlodipine 5-10 mg or Diltiazem)
🔄 Alternative Agents: Ivabradine (5-7.5 mg BID), Trimetazidine (35 mg BID), Long-acting Nitrates
⚡ Mechanism of Action & Rationale: Cardioselective beta-1 blockers have 20-100x higher affinity for cardiac beta-1 receptors than bronchial beta-2 receptors, minimizing bronchoconstriction while providing cardioprotection.
⚠️ Common Exam Trap & What to AVOID: STRICTLY CONTRAINDICATED: Non-selective beta-blockers (Propranolol, Carvedilol, Timolol, Sotalol)—can cause fatal bronchospasm and refractory status asthmaticus!
Deep vein thrombosis (DVT) & Pulmonary artery thromboembolism (PE) Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): Low Molecular Weight Heparin (Enoxaparin 1 mg/kg SC BID or 1.5 mg/kg daily) OR Direct Oral Anticoagulant (Rivaroxaban 15 mg BID for 3 weeks, then 20 mg daily; or Apixaban)
🔄 Alternative Agents: Unfractionated Heparin (UFH IV bolus + continuous infusion, target aPTT 1.5-2.5x), Fondaparinux. If MASSIVE PE with shock: Fibrinolysis (Alteplase 100 mg IV over 2 hours)
⚡ Mechanism of Action & Rationale: LMWH accelerates ATIII inhibition of Factor Xa. Rivaroxaban directly and competitively inhibits Factor Xa, interrupting both intrinsic and extrinsic coagulation cascades.
⚠️ Common Exam Trap & What to AVOID: If starting Warfarin for DVT/PE, ALWAYS overlap with Heparin/LMWH for at least 5 days and until INR is >= 2.0 for 2 consecutive days, because Warfarin causes transient hypercoagulability (early depletion of Protein C and S)!
Prophylaxis of venous thromboembolism (VTE) in surgery & obstetrics Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): Enoxaparin (20-40 mg SC once daily, starting 2-12h preoperatively or postoperatively) or Nadroparin (2850 IU anti-Xa / 0.3 ml SC daily)
🔄 Alternative Agents: UFH (5000 IU SC TID), Fondaparinux (2.5 mg SC daily post-op)
⚡ Mechanism of Action & Rationale: Inactivates Factor Xa to prevent thrombin generation and venous fibrin clot deposition in conditions of prolonged immobility and venous stasis.
⚠️ Common Exam Trap & What to AVOID: Hold LMWH at least 12-24 hours prior to spinal or epidural anesthesia/puncture to prevent spinal/epidural hematoma and permanent paraplegia!
Heparin-induced thrombocytopenia (HIT Type II) Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): IMMEDIATELY STOP all heparin (UFH & LMWH) + Start non-heparin Direct Thrombin Inhibitor (Argatroban IV infusion or Bivalirudin) or Fondaparinux
🔄 Alternative Agents: Danaparoid
⚡ Mechanism of Action & Rationale: Type II HIT is an immune-mediated reaction where antibodies against platelet factor 4 (PF4)-heparin complexes cause massive platelet activation and life-threatening paradoxical arterial and venous thrombosis.
⚠️ Common Exam Trap & What to AVOID: DO NOT transfuse platelets (fuels thrombotic fire)! DO NOT start Warfarin acutely (can cause venous limb gangrene and skin necrosis)—only start warfarin after platelet count normalizes (>150,000/mcL).
Hemorrhages due to overdose of direct-acting anticoagulants (Heparin / LMWH) Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): Protamine sulfate (1% solution IV slow infusion; 1 mg neutralizes ~100 IU of unfractionated heparin; for LMWH Enoxaparin, 1 mg per 1 mg enoxaparin)
🔄 Alternative Agents: Fresh Frozen Plasma (FFP), Stop heparin infusion
⚡ Mechanism of Action & Rationale: Protamine is a strongly basic polycationic peptide that binds to and neutralizes strongly acidic, polyanionic heparin to form an inactive, stable salt complex without anticoagulant activity.
⚠️ Common Exam Trap & What to AVOID: Protamine must be injected SLOWLY over 10 minutes; rapid IV bolus causes catastrophic anaphylactoid shock, severe hypotension, and pulmonary hypertension. Overdose of protamine itself has anticoagulant properties!
Hemorrhages due to overdose of indirect-acting anticoagulants (Warfarin / Acenocoumarol) Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): Prothrombin Complex Concentrate (PCC / 4-Factor PCC 25-50 IU/kg IV) + Phytomenadione (Vitamin K1 5-10 mg slow IV infusion)
🔄 Alternative Agents: Fresh Frozen Plasma (FFP 15 ml/kg IV) if PCC unavailable
⚡ Mechanism of Action & Rationale: PCC provides immediate, active exogenous Factors II, VII, IX, and X to restore hemostasis instantly. Vitamin K1 bypasses VKORC1 inhibition to restart endogenous hepatic gamma-carboxylation of clotting factors.
⚠️ Common Exam Trap & What to AVOID: Vitamin K1 takes 6-24 hours to synthesize new clotting factors and cannot stop acute active major bleeding alone—immediate factor replacement (PCC) is mandatory! Avoid IM injections (hematoma risk).
Hemorrhages with hyperfibrinolysis / Fibrinolytic overdose (Alteplase, Streptokinase) Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): Antifibrinolytic agents: Aminocaproic acid (5% solution, 4-5 g IV over 1h, then 1 g/h) OR Tranexamic acid (TXA 1 g IV over 10 min)
🔄 Alternative Agents: Cryoprecipitate or Fibrinogen concentrate (if fibrinogen < 1.0-1.5 g/L), Fresh Frozen Plasma
⚡ Mechanism of Action & Rationale: Competitively inhibits plasminogen activation and binds lysine-binding sites on plasmin, completely preventing the enzymatic degradation of fibrin clots.
⚠️ Common Exam Trap & What to AVOID: Avoid in active DIC with widespread microthrombosis (can trigger catastrophic fatal generalized thrombosis) and in upper urinary tract hematuria (causes ureteral clot obstruction).
Hemorrhagic disease of the newborn (Vitamin K deficiency bleeding) Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): Phytomenadione (Vitamin K1 1 mg IM or slow IV at birth / upon presentation)
🔄 Alternative Agents: Oral Vitamin K1 regimen, Fresh Frozen Plasma in severe intracranial bleeding
⚡ Mechanism of Action & Rationale: Newborns have low hepatic stores, sterile gut flora (no bacterial Vitamin K synthesis), and low breast milk Vitamin K content. Exogenous Vitamin K1 activates gamma-glutamyl carboxylase for factors II, VII, IX, X.
⚠️ Common Exam Trap & What to AVOID: Universal prophylactic Vitamin K1 IM at birth is standard of care worldwide to prevent fatal intracranial hemorrhage.
Hemophilia A and B (Congenital factor deficiency bleeding) Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): Factor VIII concentrate (recombinant or plasma-derived for Hemophilia A) / Factor IX concentrate (for Hemophilia B)
🔄 Alternative Agents: Desmopressin (DDAVP 0.3 mcg/kg IV - stimulates endogenous vWF and Factor VIII release in mild Hemophilia A); Tranexamic acid (adjunct for mucosal/dental bleeding)
⚡ Mechanism of Action & Rationale: Direct replacement of the missing intrinsic pathway coagulation factors (Factor VIII or IX) to allow normal tenase complex formation and thrombin generation.
⚠️ Common Exam Trap & What to AVOID: NEVER give Aspirin, NSAIDs, or IM injections to hemophilia patients. Desmopressin is completely INEFFECTIVE in Hemophilia B (Factor IX deficiency) and severe Hemophilia A.
Hemorrhages due to capillary fragility / Epistaxis / ENT surgeries Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): Etamsylate (Dicynone: 250-500 mg IV/IM or 500 mg oral TID) + Local hemostatics (Topical Thrombin, Epinephrine gauze, Gelatin sponge)
🔄 Alternative Agents: Tranexamic acid oral/topical, Calcium dobesilate, Ascorbic acid + Rutin (Ascorutin)
⚡ Mechanism of Action & Rationale: Etamsylate enhances platelet adhesion to subendothelial collagen via Factor III (thromboplastin) activation, increases capillary wall resistance, and reduces capillary permeability without shortening normal clotting time or inducing thrombosis.
⚠️ Common Exam Trap & What to AVOID: Etamsylate is ineffective for massive arterial hemorrhage or major factor deficiencies; it specifically treats microvascular capillary bleeding.
Disseminated Intravascular Coagulation (DIC) syndrome Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): Aggressive treatment of underlying cause (sepsis, obstetric crisis, trauma) + Hemostatic support (Platelet concentrates if <50k, Cryoprecipitate if fibrinogen <1.5 g/L, FFP for factor depletion)
🔄 Alternative Agents: Low-dose Unfractionated Heparin (5-10 IU/kg/h IV without bolus) ONLY in predominating thrombotic/hypercoagulable DIC phenotypes (e.g. solid tumors, retained dead fetus, acute promyelocytic leukemia)
⚡ Mechanism of Action & Rationale: Consumptive coagulopathy characterized by systemic microvascular thrombosis followed by exhaustion of platelets and clotting factors leading to secondary severe bleeding.
⚠️ Common Exam Trap & What to AVOID: NEVER administer antifibrinolytics (Aminocaproic acid / TXA) in DIC unless refractory severe hyperfibrinolytic bleeding with concomitant heparinization—antifibrinolytics block the natural clearance of microthrombi and cause fatal organ infarction!
Primary & secondary prevention of cerebrovascular & coronary events / TIA Hemostasis & Antithrombotics
💊 Drug of Choice (P-Drug): Acetylsalicylic acid (Aspirin 75-100 mg daily) OR Clopidogrel (75 mg daily)
🔄 Alternative Agents: Dual antiplatelet therapy (Aspirin + Clopidogrel for 21-90 days post-minor stroke/high-risk TIA), High-intensity statin
⚡ Mechanism of Action & Rationale: Aspirin permanently acetylates Serine 529 of platelet COX-1, irreversibly eliminating thromboxane A2 (TXA2) synthesis for the 7-10 day lifespan of platelets, suppressing platelet aggregation.
⚠️ Common Exam Trap & What to AVOID: Aspirin resistance or gastrointestinal ulceration/bleeding. Combine with a Proton Pump Inhibitor (Omeprazole/Pantoprazole) in high-risk patients. Avoid combining Clopidogrel with Omeprazole (CYP2C19 competition reduces clopidogrel activation; use Pantoprazole).
Essential arterial hypertension Grade I (mild, low-risk) Antihypertensive Therapy
💊 Drug of Choice (P-Drug): Lifestyle modification + Monotherapy: ACE inhibitor (Enalapril 5-10 mg or Lisinopril 10 mg) OR ARB (Losartan 50 mg) OR DHP CCB (Amlodipine 5 mg) OR Thiazide-like diuretic (Indapamide 1.5-2.5 mg)
🔄 Alternative Agents: Low-dose dual combination (ACEi + CCB or ACEi + Diuretic)
⚡ Mechanism of Action & Rationale: Reduces peripheral vascular resistance (vasodilation) and/or promotes mild natriuresis to normalize blood pressure and prevent target organ damage.
⚠️ Common Exam Trap & What to AVOID: Do not rush to multi-drug polypharmacy before lifestyle modification (salt restriction, weight loss, exercise) unless cardiovascular risk is moderate-to-high.
Essential arterial hypertension Grade III (severe >= 180/110 mmHg) Antihypertensive Therapy
💊 Drug of Choice (P-Drug): Triple fixed-dose combination: ACE inhibitor / ARB + DHP CCB (Amlodipine 10 mg) + Thiazide/Thiazide-like diuretic (Indapamide 2.5 mg or Chlorthalidone)
🔄 Alternative Agents: Add 4th line: Spironolactone (25-50 mg daily) for resistant hypertension; Alpha-blocker (Doxazosin) or Beta-blocker
⚡ Mechanism of Action & Rationale: Simultaneously targets three distinct physiological mechanisms: RAAS inhibition, arterial vasodilatation (calcium channel blockade), and sodium/volume depletion (diuretic).
⚠️ Common Exam Trap & What to AVOID: Do not lower blood pressure too abruptly unless it is an acute hypertensive emergency with acute target organ damage, to prevent watershed cerebral or myocardial ischemia.
Renovascular hypertension (Renal artery stenosis) Antihypertensive Therapy
💊 Drug of Choice (P-Drug): Calcium Channel Blocker (Amlodipine 5-10 mg) + Beta-blocker (Bisoprolol 5-10 mg) ± Revascularization (renal angioplasty/stenting)
🔄 Alternative Agents: Centrally acting agent (Moxonidine), Alpha-blocker
⚡ Mechanism of Action & Rationale: Reduces systemic vascular resistance and dampens sympathetic output without critically impairing post-stenotic glomerular filtration pressure.
⚠️ Common Exam Trap & What to AVOID: ACE INHIBITORS AND ARBs ARE STRICTLY CONTRAINDICATED IN BILATERAL RENAL ARTERY STENOSIS (or stenosis of a solitary functioning kidney)! In renal artery stenosis, glomerular filtration pressure is maintained by Angiotensin II-mediated constriction of the EFFERENT arteriole. ACEi/ARBs dilate the efferent arteriole, causing an immediate catastrophic drop in GFR and acute renal failure!
Pheochromocytoma (Diagnosis & Medical Treatment) Antihypertensive Therapy
💊 Drug of Choice (P-Drug): Treatment: Alpha-adrenoblocker FIRST (Phenoxybenzamine 10-20 mg BID-TID oral or Phentolamine 5 mg IV for acute crisis) -> followed by Beta-blocker (Propranolol/Metoprolol) after 2-3 days of established alpha blockade. Diagnosis: Plasma/urinary free metanephrines (Phentolamine suppression test historically).
🔄 Alternative Agents: Doxazosin (selective alpha-1 blocker), Labetalol (combined alpha/beta blocker, once alpha block is established)
⚡ Mechanism of Action & Rationale: Alpha-blockade relieves the massive catecholamine-induced alpha-1 vasoconstriction, controls blood pressure, and expands intravascular volume. Beta-blocker then controls reflex/catecholamine tachycardia.
⚠️ Common Exam Trap & What to AVOID: CARDINAL EXAM TRAP: NEVER GIVE A BETA-BLOCKER ALONE BEFORE AN ALPHA-BLOCKER IN PHEOCHROMOCYTOMA! Beta-2 receptors mediate vasodilation; blocking them leaves massive circulating epinephrine/norepinephrine acting exclusively on alpha-1 receptors, causing catastrophic malignant hypertension, pulmonary edema, or intracranial hemorrhage!
Hypertensive emergencies in eclampsia & pre-eclampsia (Pregnancy) Antihypertensive Therapy
💊 Drug of Choice (P-Drug): IV Magnesium sulfate (4-6 g IV loading over 15-20 min, then 1-2 g/h continuous infusion to prevent/treat seizures) + IV Labetalol (20 mg IV bolus, then 40-80 mg every 10 min) OR IV Hydralazine (5-10 mg slow IV) OR Oral Nifedipine retard (10-20 mg)
🔄 Alternative Agents: Methyldopa (oral 250-500 mg TID - mainstay for chronic HTA in pregnancy), Nicardipine IV
⚡ Mechanism of Action & Rationale: Magnesium sulfate inhibits NMDA receptors and decreases acetylcholine release at motor endplates, preventing eclamptic convulsions. Labetalol and Hydralazine provide rapid, safe maternal BP reduction without compromising uteroplacental perfusion.
⚠️ Common Exam Trap & What to AVOID: ABSOLUTELY CONTRAINDICATED IN PREGNANCY: ACE inhibitors, ARBs, Direct Renin Inhibitors (severe fetotoxicity: renal agenesis, skull hypoplasia, oligohydramnios, fetal death), Nitroprusside (fetal cyanide toxicity), and Diuretics (decrease placental blood flow).
Hypertensive emergencies in hypertensive encephalopathy Antihypertensive Therapy
💊 Drug of Choice (P-Drug): IV Labetalol (20-80 mg IV bolus every 10 min or infusion 0.5-2 mg/min) OR IV Nicardipine (5-15 mg/h infusion) OR IV Sodium Nitroprusside (0.3-10 mcg/kg/min)
🔄 Alternative Agents: Clevidipine IV, Urapidil IV (5-HT1A + alpha-1 blocker)
⚡ Mechanism of Action & Rationale: Rapidly controls severe blood pressure to reduce cerebral hyperperfusion, breakdown of blood-brain barrier, and cerebral edema.
⚠️ Common Exam Trap & What to AVOID: Do NOT lower mean arterial pressure (MAP) by more than 20-25% in the first hour, or to <160/100 mmHg over the first 2-6 hours. Autoregulation is shifted to the right in chronic hypertension; precipitous drops cause cerebral infarction and coma!
Arterial hypertension with associated diabetes mellitus Antihypertensive Therapy
💊 Drug of Choice (P-Drug): ACE inhibitor (Captopril, Enalapril, Lisinopril) OR Angiotensin Receptor Blocker (Losartan, Valsartan) ± DHP CCB (Amlodipine)
🔄 Alternative Agents: Indapamide (metabolically neutral diuretic)
⚡ Mechanism of Action & Rationale: Selectively dilates the renal efferent arteriole, decreasing intraglomerular hydrostatic pressure, significantly reducing microalbuminuria and slowing diabetic nephropathy progression; improves insulin sensitivity.
⚠️ Common Exam Trap & What to AVOID: Avoid high-dose Thiazide diuretics (impair pancreatic insulin secretion -> worsen hyperglycemia) and high-dose non-selective beta-blockers (mask hypoglycemic warning symptoms like tachycardia and tremors, leaving only diaphoresis).
Arterial hypertension in young patients (hyperadrenergic, high renin) Antihypertensive Therapy
💊 Drug of Choice (P-Drug): Beta-adrenoblocker (Bisoprolol 2.5-5 mg daily or Nebivolol 5 mg daily) OR ACE inhibitor (Enalapril 10-20 mg daily)
🔄 Alternative Agents: ARB (Losartan 50 mg daily)
⚡ Mechanism of Action & Rationale: Suppresses elevated sympathetic tone, lowers high cardiac output, and blocks elevated juxtaglomerular renin release.
⚠️ Common Exam Trap & What to AVOID: Young patients may suffer from erectile dysfunction with beta-blockers (Nebivolol has lower incidence due to NO release). Screen for secondary causes of hypertension (coarctation of aorta, renal artery stenosis, pheochromocytoma).
Arterial hypertension in elderly patients (Isolated Systolic HTA) Antihypertensive Therapy
💊 Drug of Choice (P-Drug): Dihydropyridine CCB (Amlodipine 5-10 mg or Lercanidipine 10-20 mg) OR Thiazide-like diuretic (Indapamide 1.5-2.5 mg)
🔄 Alternative Agents: ACE inhibitor or ARB
⚡ Mechanism of Action & Rationale: Directly counteracts age-related arterial stiffness and elevated systemic vascular resistance without impairing cerebral autoregulation or causing severe orthostasis.
⚠️ Common Exam Trap & What to AVOID: Avoid Centrally Acting agents (Clonidine, Methyldopa - cause severe sedation, cognitive impairment, depression, falls) and Alpha-1 blockers (Prazosin - severe orthostatic hypotension and syncope).
Controlled hypotension during surgery (anesthesia) Antihypertensive Therapy
💊 Drug of Choice (P-Drug): Sodium Nitroprusside IV infusion (0.3-5 mcg/kg/min) OR Nitroglycerin IV infusion OR Esmolol IV infusion
🔄 Alternative Agents: Ganglioplegics (Trimethaphan, Trepirium historically), Nicardipine IV
⚡ Mechanism of Action & Rationale: Ultra-short-acting direct arteriolar and venous vasodilatation reduces arterial blood pressure to ~80-90 mmHg systolic, minimizing surgical blood loss in microvascular/orthopedic/ENT operations.
⚠️ Common Exam Trap & What to AVOID: Sodium nitroprusside infusion > 72h or at high rates can cause lethal Cyanide and Thiocyanate poisoning (lactic acidosis, confusion, convulsions). Administer Sodium thiosulfate or Hydroxocobalamin as antidote.
Cardiogenic shock (Pump Failure / Acute MI) Antihypotensives & Shock
💊 Drug of Choice (P-Drug): Inotrope / Vasopressor: Norepinephrine IV (0.05-0.5 mcg/kg/min if severe hypotension SBP < 70-80) + Dobutamine IV (2.5-15 mcg/kg/min for contractility) ± Mechanical support (IABP / Impella)
🔄 Alternative Agents: Dopamine IV (5-10 mcg/kg/min), Levosimendan, Milrinone (if SBP adequate)
⚡ Mechanism of Action & Rationale: Dobutamine stimulates beta-1 receptors to augment stroke volume and cardiac output. Norepinephrine restores adequate coronary and cerebral perfusion pressure via alpha-1 vasoconstriction.
⚠️ Common Exam Trap & What to AVOID: Do NOT give fluid boluses in cardiogenic shock with pulmonary congestion/edema! High-dose Dopamine or pure vasoconstrictors (Phenylephrine) increase afterload and myocardial oxygen consumption, worsening ischemic failure.
Hypotonic arterial hypotension / Vasomotor collapse / Septic shock Antihypotensives & Shock
💊 Drug of Choice (P-Drug): First-line Vasopressor: Norepinephrine IV infusion (0.05-1.0 mcg/kg/min) + IV Crystalloids (30 ml/kg balanced crystalloid bolus)
🔄 Alternative Agents: Vasopressin (0.03 units/min as adjunct), Epinephrine IV (if refractory), Hydrocortisone IV (200 mg/day for refractory septic shock)
⚡ Mechanism of Action & Rationale: Norepinephrine stimulates vascular alpha-1 and alpha-2 receptors, restoring systemic vascular resistance and mean arterial pressure without excessive tachycardia.
⚠️ Common Exam Trap & What to AVOID: Do NOT rely on Dopamine as first-line in septic shock (higher incidence of tachyarrhythmias and excess mortality). Do not delay vasopressors while waiting for complete fluid resuscitation if MAP < 65 mmHg.
Hypertonic arterial hypotension (Cardiac hypotension / massive acute MI with high SVR) Antihypotensives & Shock
💊 Drug of Choice (P-Drug): Positive Inotrope (Dobutamine IV 2.5-10 mcg/kg/min or Milrinone IV) + Cautious Vasodilator (Nitroglycerin IV or Nitroprusside IV once BP stabilizes)
🔄 Alternative Agents: Levosimendan IV infusion, Intra-aortic balloon counterpulsation (IABP)
⚡ Mechanism of Action & Rationale: Increases stroke volume and cardiac output while cautiously reducing elevated afterload (systemic vascular resistance) to unload the failing left ventricle.
⚠️ Common Exam Trap & What to AVOID: Avoid high-dose alpha-adrenomimetics (Phenylephrine, Norepinephrine) which dramatically increase afterload and can cause acute left ventricular rupture or intractable pulmonary edema.
Orthostatic hypotension (idiopathic or drug-induced by alpha-blockers) Antihypotensives & Shock
💊 Drug of Choice (P-Drug): Midodrine (oral 2.5-10 mg TID) OR Fludrocortisone (oral 0.1-0.2 mg daily) + Physical measures (compression stockings, adequate hydration and salt intake)
🔄 Alternative Agents: Droxidopa (prodrug of NE), Pyridostigmine, Ephedrine
⚡ Mechanism of Action & Rationale: Midodrine is an oral selective alpha-1 adrenergic prodrug that increases venous tone and arteriolar resistance. Fludrocortisone is a synthetic mineralocorticoid that expands plasma volume and sensitizes vascular receptors to catecholamines.
⚠️ Common Exam Trap & What to AVOID: Supine hypertension: Midodrine should not be taken within 4 hours of bedtime. Raise head of bed by 10-15 degrees.
Chronic arterial hypotension / Neurocirculatory asthenia Antihypotensives & Shock
💊 Drug of Choice (P-Drug): Central analeptics & CNS tonics: Caffeine sodium benzoate (oral 100-200 mg or 2% sol. 1-2 ml SC/IM) OR Herbal adaptogens (Ginseng tincture, Eleutherococcus extract 20-30 drops BID-TID)
🔄 Alternative Agents: Cordiamine (Nikethamide 25% drops/sol.), Camphor / Sulfocamphocain, Midodrine
⚡ Mechanism of Action & Rationale: Stimulates the vasomotor and respiratory centers in the medulla oblongata, antagonizes inhibitory adenosine A1/A2A receptors, improves sympathetic vasomotor tone and cerebral alertness.
⚠️ Common Exam Trap & What to AVOID: Rule out secondary causes (Addison's disease, hypothyroidism, chronic blood loss, heart failure) before diagnosing constitutional/chronic essential hypotension.
Arterial hypotension resistant to alpha-adrenomimetics (Refractory Vasoplegic Shock) Antihypotensives & Shock
💊 Drug of Choice (P-Drug): Glucocorticoids (Hydrocortisone 100 mg IV every 8h) + Vasopressin IV (0.03 units/min) OR Methylene Blue IV (1.5-2 mg/kg bolus)
🔄 Alternative Agents: Angiotensin II infusion (Giapreza)
⚡ Mechanism of Action & Rationale: Glucocorticoids exert a 'permissive effect', upregulating downregulated alpha-1 adrenoreceptors and restoring vascular responsiveness to catecholamines. Methylene blue inhibits inducible nitric oxide synthase (iNOS) and soluble guanylyl cyclase.
⚠️ Common Exam Trap & What to AVOID: Refractory hypotension often stems from relative adrenal insufficiency or severe metabolic acidosis. High doses of catecholamines without glucocorticoids fail due to receptor desensitization.

💊 Sequence 1.2: Official Medical Prescription Vault

Master all 44 official drugs (49 syllabus items) with standard Latin prescription formulas (Rp.:, D.t.d., S.), official pharmaceutical strengths, detailed cellular mechanisms of action, and exact clinical dosing regimens.

#1 Strophanthin (Strophanthinum)
Official Forms: Solution 0.025% - 1 ml ampoules
PDF 1 (#1) - Cardiotonic Glycoside (Fast/Short)
⚡ Mechanism of Action (MOA):
Reversibly inhibits the sarcolemmal Na+/K+-ATPase pump in cardiomyocytes -> accumulates intracellular Na+ -> suppresses and reverses the 3Na+/1Ca2+ exchanger (NCX) -> increases intracellular Ca2+ loading in the sarcoplasmic reticulum -> produces rapid, powerful positive inotropy on systole. Simultaneously exerts vagomimetic effects slowing SA/AV nodal conduction.
Rp.: Sol. Strophanthini 0.025% - 1 ml D.t.d. N. 10 in ampullis S. For IV infusion: dilute 0.5-1 ml in 20 ml of 5% glucose or 0.9% NaCl solution, administer slowly over 10-15 minutes, 1-2 times daily.
Clinical Dosage Regimen: Acute heart failure / Acute pulmonary edema with tachyarrhythmia: 0.25-0.5 mg (1-2 ml) diluted slowly IV under ECG monitoring. Rapid onset (5-10 min), short duration (1-3 days), minimal cumulative effect.
Key Examination Pearls: High polarity, no oral absorption, purely renal excretion. Rapid digitalization drug of choice for acute emergency decompensation.
#2 Digoxin (Digoxinum)
Official Forms: Tablets 0.00025 (0.25 mg); Solution 0.025% - 1 ml ampoules
PDF 1 (#2) - Cardiotonic Glycoside (Intermediate)
⚡ Mechanism of Action (MOA):
Reversibly inhibits the sarcolemmal Na+/K+-ATPase pump -> increases intracellular Na+ -> decreases Ca2+ extrusion via the 3Na+/1Ca2+ antiporter (NCX) -> increases sarcoplasmic reticulum Ca2+ storage and systolic release -> produces positive inotropy. Concurrently stimulates central and nodose parasympathetic vagal nuclei -> slows SA node firing and prolongs AV nodal refractoriness (negative chronotropy & negative dromotropy).
Rp.: Tab. Digoxini 0.00025 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (0.25 mg) once daily in the morning after meal. Rp.: Sol. Digoxini 0.025% - 1 ml D.t.d. N. 10 in ampullis S. For IV injection: dilute 1-2 ml in 20 ml of 0.9% NaCl, inject slowly IV over 5-10 minutes.
Clinical Dosage Regimen: Chronic Heart Failure (NYHA II-IV) & AFib rate control: Slow digitalization: 0.125-0.25 mg daily maintenance. Moderate digitalization: 0.5-0.75 mg daily divided for 2-3 days, then maintenance. Target therapeutic plasma level: 0.5-0.9 ng/ml.
Key Examination Pearls: Narrow therapeutic index. Toxicity triggered by hypokalemia, hypercalcemia, hypomagnesemia, and quinidine/verapamil co-administration.
#3 Captopril (Captoprilum)
Official Forms: Tablets 0.0125 (12.5 mg); 0.025 (25 mg); 0.05 (50 mg)
PDF 1 (#3) & PDF 2 (#10) - ACE Inhibitor (Short-Acting, Sulfhydryl)
⚡ Mechanism of Action (MOA):
Competitive inhibitor of Angiotensin-Converting Enzyme (ACE / kininase II) -> blocks conversion of Angiotensin I to Angiotensin II, reducing arteriolar vasoconstriction and aldosterone-mediated sodium/water retention; simultaneously prevents the degradation of vasodilatory Bradykinin and Substance P, causing balanced arterial and venous dilation and reducing both preload and afterload.
Rp.: Tab. Captoprili 0.025 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (25 mg) 2-3 times daily, 1 hour before meals.
Clinical Dosage Regimen: Hypertensive crises / Urgencies: 12.5-25 mg sublingually or orally; rapid onset (15-30 min). Heart failure / Post-MI / Diabetic nephropathy: start 6.25-12.5 mg TID, titrate up to 50 mg TID.
Key Examination Pearls: Active drug (not a prodrug). Contains -SH group causing taste alteration (dysgeusia) and neutropenia/rash. Watch for dry cough (bradykinin) and hyperkalemia.
#4 Nifedipine (Nifedipinum)
Official Forms: Tablets 0.01 (10 mg); 0.02 (20 mg) [retard]
PDF 1 (#4) & PDF 2 (#8) - Dihydropyridine CCB (1st Gen)
⚡ Mechanism of Action (MOA):
Selectively binds to and blocks voltage-gated L-type calcium channels (Cav1.2) in vascular smooth muscle cells -> prevents trans-sarcolemmal Ca2+ influx -> inhibits calmodulin-activated myosin light chain kinase (MLCK) -> produces potent peripheral arteriolar and epicardial coronary vasodilation, markedly decreasing systemic vascular resistance (afterload) and relieving coronary vasospasm.
Rp.: Tab. Nifedipini 0.01 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (10 mg) 2-3 times daily with meals. Rp.: Tab. Nifedipini retard 0.02 N. 30 D.t.d. N. 30 S. Orally, 1 retard tablet (20 mg) 1-2 times daily swallowed whole.
Clinical Dosage Regimen: Vasospastic (Prinzmetal) Angina & Chronic Stable Angina: 10-20 mg 2-3 times daily. Hypertension (in pregnancy or resistant): Retard formulation 20-40 mg daily. Preeclampsia emergency: 10-20 mg oral capsule.
Key Examination Pearls: Potent peripheral and coronary arteriolar dilator. Short-acting nifedipine without beta-blocker is contraindicated in ACS (causes reflex tachycardia and 'coronary steal').
#5 Enalapril (Enalaprilum)
Official Forms: Tablets 0.005 (5 mg); 0.01 (10 mg); 0.02 (20 mg); Solution 0.125% - 1 ml ampoules (Enalaprilat)
PDF 1 (#5) & PDF 2 (#11) - ACE Inhibitor (Prodrug)
⚡ Mechanism of Action (MOA):
Prodrug bioactivated by hepatic esterases to Enalaprilat, which competitively inhibits ACE (kininase II) -> suppresses Angiotensin II synthesis and Aldosterone secretion while preventing Bradykinin breakdown -> produces systemic arteriolar and venous dilation, halts adverse cardiac remodeling, and reduces both preload and afterload.
Rp.: Tab. Enalaprili 0.01 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (10 mg) once or twice daily, irrespective of meals. Rp.: Sol. Enalaprilati 0.125% - 1 ml D.t.d. N. 5 in ampullis S. For IV injection: 1 ml (1.25 mg) slow IV over 5 minutes every 6 hours.
Clinical Dosage Regimen: Essential Hypertension: initial 5 mg daily, maintenance 10-20 mg once or twice daily (max 40 mg). Heart Failure (NYHA II-IV): start 2.5 mg BID, titrate to 10-20 mg BID. Hypertensive emergencies: IV enalaprilat 1.25 mg every 6 hours.
Key Examination Pearls: Prodrug bioactivated to Enalaprilat by hepatic esterases. Contraindicated in pregnancy (teratogenic) and bilateral renal artery stenosis.
#6 Lisinopril (Lisinoprilum)
Official Forms: Tablets 0.005 (5 mg); 0.01 (10 mg); 0.02 (20 mg)
PDF 1 (#6) - ACE Inhibitor (Water-Soluble, Non-Prodrug)
⚡ Mechanism of Action (MOA):
Direct active lysine analogue of enalaprilat (non-prodrug); competitively inhibits ACE -> decreases Angiotensin II and Aldosterone levels while increasing Bradykinin -> produces systemic vasodilation and natriuresis; selectively dilates the renal efferent arteriole, lowering intraglomerular hydrostatic pressure and preventing diabetic glomerulosclerosis.
Rp.: Tab. Lisinoprili 0.01 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (10 mg) once daily in the morning.
Clinical Dosage Regimen: Arterial Hypertension & Diabetic Nephropathy: start 10 mg once daily, titrate to 20-40 mg daily. Post-Myocardial Infarction: 5 mg within 24h, 5 mg at 24h, 10 mg at 48h, then 10 mg daily for 6 weeks.
Key Examination Pearls: Active lysine analogue of enalaprilat; does not require hepatic metabolism; excreted unchanged by the kidneys. Excellent in patients with hepatic impairment.
#7 Bisoprolol (Bisoprololum)
Official Forms: Tablets 0.0025 (2.5 mg); 0.005 (5 mg); 0.01 (10 mg)
PDF 1 (#7) & PDF 2 (#5) - Cardioselective Beta-1 Blocker
⚡ Mechanism of Action (MOA):
Highly selective competitive Beta-1 adrenoreceptor antagonist (beta-1/beta-2 selectivity ratio ~20:1) -> blocks Gs-protein adenylyl cyclase activation -> decreases intracellular cAMP and protein kinase A (PKA) -> decreases Phase 4 spontaneous depolarization in the SA node, slows AV conduction, reduces myocardial contractility, and suppresses juxtaglomerular renin secretion.
Rp.: Tab. Bisoprololi 0.005 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (5 mg) once daily in the morning before breakfast.
Clinical Dosage Regimen: Hypertension & Stable Angina: 5-10 mg once daily. Chronic Heart Failure (HFrEF): start at 1.25 mg daily, double every 2-4 weeks as tolerated (1.25 -> 2.5 -> 3.75 -> 5 -> 7.5 -> 10 mg target daily).
Key Examination Pearls: High beta-1 selectivity (beta1/beta2 ratio ~20:1). Balanced dual elimination (50% liver, 50% kidney). One of the 3 proven beta-blockers for reducing mortality in HF.
#8 Trimetazidine (Trimetazidinum)
Official Forms: Tablets 0.035 (35 mg) [modified release]
PDF 1 (#8) - Metabolic Antianginal / Cytoprotector
⚡ Mechanism of Action (MOA):
Selectively inhibits mitochondrial long-chain 3-ketoacyl-CoA thiolase (3-KAT) -> shifts myocardial energy substrate metabolism from fatty acid beta-oxidation to glucose oxidation (which requires less oxygen per mole of ATP generated) -> preserves cellular ATP levels, maintains intracellular ionic homeostasis, and protects cardiomyocytes during ischemia without altering heart rate, BP, or hemodynamics.
Rp.: Tab. Trimetazidini 0.035 N. 60 D.t.d. N. 60 S. Orally, 1 tablet (35 mg) twice daily with meals (morning and evening).
Clinical Dosage Regimen: Add-on therapy for symptomatic chronic stable angina: 35 mg BID. Inhibits mitochondrial 3-ketoacyl-CoA thiolase (3-KAT), shifting myocardial energy metabolism from fatty acid beta-oxidation to glucose oxidation, preserving intracellular ATP.
Key Examination Pearls: No hemodynamic effects (does not alter heart rate or BP). Contraindicated in Parkinson's disease and severe renal failure.
#9 Lidocaine (Lidocainum)
Official Forms: Solution 2%, 10% - 2 ml; Solution 1%, 2% - 20 ml ampoules
PDF 1 (#9) - Class IB Antiarrhythmic & Local Anesthetic
⚡ Mechanism of Action (MOA):
Class IB antiarrhythmic; selectively binds and blocks open and inactivated voltage-gated fast Na+ channels (Nav1.5) with rapid association and dissociation kinetics; acts preferentially on depolarized, ischemic, or rapidly firing ventricular myocytes -> decreases Phase 0 velocity, shortens action potential duration (APD) and effective refractory period (ERP) in ventricles without depressing normal atrial or AV nodal conduction.
Rp.: Sol. Lidocaini 2% - 2 ml D.t.d. N. 10 in ampullis S. For IV injection: initial loading bolus 1-1.5 mg/kg (50-100 mg = 2.5-5 ml of 2% sol.) IV over 2-3 min, followed by continuous IV infusion 1-4 mg/min.
Clinical Dosage Regimen: Ventricular arrhythmias in Acute Myocardial Infarction & Digitalis-induced ventricular tachyarrhythmias: 1-1.5 mg/kg IV bolus, maintenance 1-4 mg/min. Local infiltration anesthesia: 0.5-2% solution.
Key Examination Pearls: Selective block of open/inactivated Na+ channels in ischemic/depolarized tissue. No effect on supraventricular tissue! High first-pass hepatic metabolism (IV only for arrhythmias). CNS toxicity: tremors, drowsiness, convulsions.
#10 Metoprolol (Metoprololum)
Official Forms: Tablets 0.025 (25 mg); 0.05 (50 mg); 0.1 (100 mg)
PDF 1 (#10) & PDF 2 (#4) - Cardioselective Beta-1 Blocker
⚡ Mechanism of Action (MOA):
Cardioselective Beta-1 adrenoreceptor antagonist -> blocks catecholamine-induced adenylyl cyclase stimulation -> decreases heart rate, myocardial contractility, stroke volume, and systolic BP -> reduces myocardial oxygen consumption (MVO2), prevents stress-induced ischemia, and suppresses ectopic ventricular and supraventricular automaticity.
Rp.: Tab. Metoprololi 0.05 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (50 mg) twice daily after meals. Rp.: Tab. Metoprololi succinatis retard 0.1 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (100 mg) once daily in the morning.
Clinical Dosage Regimen: Hypertension & Angina Pectoris: 50-100 mg daily in 1-2 divided doses. Post-MI secondary prevention: 50 mg BID for 48h, then 100 mg BID. Chronic HF: Metoprolol succinate extended-release start 12.5-25 mg daily, target 200 mg daily.
Key Examination Pearls: Metoprolol tartrate = short-acting (BID); Metoprolol succinate = long-acting (once daily, mortality benefit in MERIT-HF). Moderately lipophilic, extensive hepatic metabolism (CYP2D6).
#11 Amiodarone (Amiodaronum)
Official Forms: Tablets 0.2 (200 mg); Solution 5% - 3 ml (150 mg) ampoules
PDF 1 (#11) - Class III Multi-Channel Antiarrhythmic
⚡ Mechanism of Action (MOA):
Multi-channel antiarrhythmic; predominantly Class III (blocks delayed rectifier K+ currents IKr and IKs, prolonging Phase 3 repolarization, APD, and ERP across all cardiac tissues), with significant Class I (inactivated fast Na+ channel block), Class II (non-competitive beta-adrenoreceptor antagonism), Class IV (L-type Ca2+ channel block), and vascular alpha-1 receptor blockade.
Rp.: Tab. Amiodaroni 0.2 N. 30 D.t.d. N. 30 S. Orally, loading dose 1 tablet (200 mg) 3 times daily for 8-14 days, then maintenance 200 mg once daily. Rp.: Sol. Amiodaroni 5% - 3 ml D.t.d. N. 5 in ampullis S. For IV infusion: 300 mg (2 ampoules) diluted in 250 ml of 5% glucose solution, infuse over 20-60 minutes.
Clinical Dosage Regimen: Life-threatening Ventricular Tachycardia / VF & Atrial Fibrillation conversion/maintenance: Loading 600-800 mg daily oral for 1-2 weeks, maintenance 100-200 mg daily. ACLS pulseless VT/VF: 300 mg IV bolus diluted in 20 ml D5W.
Key Examination Pearls: Possesses Class I, II, III, IV actions. Enormous volume of distribution; elimination t1/2 ~50-60 days! Adverse effects: pulmonary fibrosis, hypo/hyperthyroidism (iodine content), corneal microdeposits, slate-blue skin, QT prolongation (low torsades risk).
#12 Verapamil (Verapamilum)
Official Forms: Tablets 0.08 (80 mg)
PDF 1 (#12) - Class IV Antiarrhythmic / Non-DHP CCB
⚡ Mechanism of Action (MOA):
Class IV non-dihydropyridine calcium channel blocker (phenylalkylamine); binds the intracellular alpha-1 subunit of L-type Ca2+ channels in the SA and AV nodes in a use- and frequency-dependent manner -> suppresses Phase 0 slow calcium upstroke and Phase 4 diastolic depolarization -> markedly slows AV nodal conduction velocity, prolongs AV refractoriness, and exerts direct negative inotropy and negative chronotropy.
Rp.: Tab. Verapamili 0.08 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (80 mg) 3 times daily with meals.
Clinical Dosage Regimen: PSVT prophylaxis, AFib/AFlutter rate control, Angina pectoris: 80-120 mg TID. Acute PSVT termination: 5-10 mg slow IV over 2 min.
Key Examination Pearls: Phenylalkylamine CCB; acts predominantly on cardiac L-type Ca2+ channels (SA and AV node). Causes bradycardia, AV block, constipation. CARDINAL CONTRAINDICATION: IV Verapamil + IV Beta-blocker causes fatal asystole!
#13 Potassium chloride (Kalii chloridum)
Official Forms: Solution 4% - 10 ml; Solution 15% - 20 ml ampoules
PDF 1 (#13) - Electrolyte / Antiarrhythmic Adjunct
⚡ Mechanism of Action (MOA):
Restores the physiological extracellular-to-intracellular K+ concentration gradient across the myocardial sarcolemma -> restores normal negative resting membrane potential (-90 mV) -> accelerates Phase 3 repolarization via delayed rectifier and inward rectifier (IK1) channels, terminating digitalis- or hypokalemia-induced delayed afterdepolarizations (DADs) and abnormal automaticity.
Rp.: Sol. Kalii chloridi 4% - 10 ml D.t.d. N. 10 in ampullis S. For IV drip infusion: dilute 10-20 ml (1-2 ampoules) in 500 ml of 5% glucose or 0.9% NaCl solution, infuse at a rate not exceeding 20 mmol K+/hour.
Clinical Dosage Regimen: Hypokalemia, Digitalis toxicity arrhythmias, Diuretic-induced potassium depletion: IV infusion strictly diluted; never give undiluted IV push! Target serum potassium 4.0-5.0 mmol/L in cardiac patients.
Key Examination Pearls: Rapid or concentrated IV potassium administration induces instant fatal ventricular fibrillation and cardiac arrest!
#14 Sotalol (Sotalolum)
Official Forms: Tablets 0.08 (80 mg)
PDF 1 (#14) - Class III Antiarrhythmic with Non-selective Beta-block
⚡ Mechanism of Action (MOA):
Class III antiarrhythmic with non-selective beta-adrenoreceptor blocking properties (racemic d,l-sotalol); blocks delayed rectifier K+ channels (IKr) -> prolongs cardiac action potential duration and effective refractory period throughout atria and ventricles; also competitively blocks Beta-1 and Beta-2 receptors, suppressing sympathetic arrhythmogenesis.
Rp.: Tab. Sotaloli 0.08 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (80 mg) twice daily, 1 hour before meals.
Clinical Dosage Regimen: Supraventricular and Ventricular Arrhythmias (AFib rhythm maintenance, recurrent VT): start 80 mg BID, titrate to 160 mg BID. Purely renal excretion.
Key Examination Pearls: Prolongs cardiac action potential duration and QT interval. High risk of Torsades de Pointes, especially in hypokalemia, hypomagnesemia, and renal failure. Monitor QTc continuously.
#15 Heparin sodium (Heparinum natricum)
Official Forms: Solution 5000 IU/ml – 5 ml, 10 ml ampoules; Gel 1000 IU/g – 30.0; 50.0; 100.0
PDF 1 (#15) - Direct Anticoagulant (Unfractionated)
⚡ Mechanism of Action (MOA):
Binds specifically to Antithrombin III (ATIII) via a unique high-affinity pentasaccharide sequence -> induces an irreversible 1000-fold conformational activation of ATIII -> accelerates ATIII-mediated proteolytic neutralization of Thrombin (Factor IIa) and Factor Xa in an equal 1:1 stoichiometric ratio, as well as Factors IXa, XIa, and XIIa, halting fibrin clot propagation.
Rp.: Sol. Heparini natrici 5000 IU/ml – 5 ml D.t.d. N. 5 in ampullis S. For IV injection: initial bolus 5000 IU (1 ml) IV, followed by continuous IV infusion 1000-1500 IU/h (20,000-30,000 IU/day) adjusted to maintain aPTT 1.5-2.5x control. Rp.: Gel Heparini 1000 IU/g – 50.0 D.S. External use: apply a thin layer to the affected skin area 2-3 times daily (for superficial thrombophlebitis).
Clinical Dosage Regimen: DVT/PE treatment, STEMI, ACS, cardiopulmonary bypass: IV bolus 60-80 IU/kg, then 12-18 IU/kg/h. VTE prophylaxis: 5000 IU SC every 8-12 hours.
Key Examination Pearls: Antithrombin III dependent (inhibits IIa and Xa 1:1). Monitor aPTT. Watch for HIT (Type II) and osteoporosis on chronic use. Antidote: Protamine sulfate (1 mg per 100 IU heparin).
#16 Nadroparin calcium (Nadroparinum calcicum)
Official Forms: Prefilled syringes: 2850 IU anti-Xa / 0.3 ml; 5700 IU anti-Xa / 0.6 ml; 7600 IU anti-Xa / 0.8 ml
PDF 1 (#16) - Low Molecular Weight Heparin (LMWH)
⚡ Mechanism of Action (MOA):
Low molecular weight heparin (depolymerized heparin fragments); binds ATIII to accelerate neutralization of coagulation proteases, demonstrating high selectivity for Factor Xa over Thrombin (anti-Xa to anti-IIa activity ratio ~3.5:1), preventing prothrombinase complex activation with high subcutaneous bioavailability.
Rp.: Sol. Nadroparini calcici 2850 IU anti-Xa / 0.3 ml D.t.d. N. 10 in syringis praerepletis S. Subcutaneously: inject 0.3 ml (2850 IU) into the anterolateral abdominal wall once daily for 7-10 days (for surgical VTE prophylaxis).
Clinical Dosage Regimen: VTE prophylaxis in general surgery: 2850 IU SC once daily. VTE treatment: 86 IU anti-Xa/kg SC twice daily. High-risk orthopedic surgery: 38 IU anti-Xa/kg pre-op, titrated post-op.
Key Examination Pearls: Higher anti-Xa to anti-IIa ratio (~3.5:1). Long plasma half-life, high bioavailability (98%), no routine coagulation monitoring required.
#17 Enoxaparin sodium (Enoxaparinum natricum)
Official Forms: Prefilled syringes: 2000 IU (20 mg)/0.2 ml; 4000 IU (40 mg)/0.4 ml; 8000 IU (80 mg)/0.8 ml; 10000 IU (100 mg)/1 ml
PDF 1 (#17) - Low Molecular Weight Heparin (LMWH)
⚡ Mechanism of Action (MOA):
Low molecular weight heparin (mean MW ~4.5 kDa); complexes with ATIII to selectively inactivate Factor Xa with minimal anti-thrombin activity (anti-Factor Xa to anti-IIa ratio 3.8:1 to 4:1) -> interrupts the final common pathway of the coagulation cascade, halting thrombin generation and fibrin clot formation.
Rp.: Sol. Enoxaparini natrici 4000 IU (40 mg) / 0.4 ml D.t.d. N. 10 in syringis praerepletis S. Subcutaneously: inject 0.4 ml (40 mg) into the abdominal wall once daily for 7-10 days (for VTE prophylaxis). Rp.: Sol. Enoxaparini natrici 8000 IU (80 mg) / 0.8 ml D.t.d. N. 10 in syringis praerepletis S. Subcutaneously: inject 0.8 ml (80 mg = 1 mg/kg) every 12 hours for DVT/PE treatment or ACS.
Clinical Dosage Regimen: DVT/PE treatment & ACS: 1 mg/kg (100 IU/kg) SC BID OR 1.5 mg/kg SC once daily. Surgical VTE prophylaxis: 20-40 mg SC once daily. STEMI (<75 yrs): 30 mg IV bolus + 1 mg/kg SC BID.
Key Examination Pearls: Anti-Xa:IIa ratio 3.8:1. Primarily eliminated by kidneys (reduce dose by 50% if CrCl < 30 ml/min). Lower HIT incidence than UFH. Antidote: Protamine sulfate (partially neutralizes ~60%).
#18 Rivaroxaban (Rivaroxabanum)
Official Forms: Tablets 0.0025 (2.5 mg); 0.01 (10 mg); 0.015 (15 mg); 0.02 (20 mg)
PDF 1 (#18) - Direct Oral Anticoagulant (Direct Factor Xa Inhibitor)
⚡ Mechanism of Action (MOA):
Direct oral anticoagulant (DOAC); selective, reversible, competitive inhibitor of both free and clot-bound Factor Xa within the prothrombinase complex -> directly blocks the conversion of prothrombin (Factor II) to thrombin (Factor IIa) without requiring antithrombin III as a cofactor.
Rp.: Tab. Rivaroxabani 0.02 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (20 mg) once daily with evening meal (for stroke prevention in non-valvular AFib). Rp.: Tab. Rivaroxabani 0.015 N. 42 D.t.d. N. 1 S. Orally, 1 tablet (15 mg) twice daily with food for 21 days (for acute DVT/PE), then switch to 20 mg once daily.
Clinical Dosage Regimen: Non-valvular AFib: 20 mg once daily with food (15 mg if CrCl 15-49 ml/min). Acute DVT/PE: 15 mg BID for 3 weeks, then 20 mg once daily. CAD/PAD secondary prevention: 2.5 mg BID + Aspirin.
Key Examination Pearls: Rapid onset (2-4h). No routine coagulation monitoring. 15 mg and 20 mg tablets MUST be taken with food to ensure high oral bioavailability. Specific antidote: Andexanet alfa.
#19 Warfarin (Warfarinum)
Official Forms: Tablets 0.003 (3 mg); 0.005 (5 mg)
PDF 1 (#19) - Indirect Anticoagulant (Vitamin K Antagonist)
⚡ Mechanism of Action (MOA):
Competitive inhibitor of Vitamin K Epoxide Reductase Complex 1 (VKORC1) -> blocks enzymatic regeneration of reduced Vitamin K hydroquinone -> prevents hepatic gamma-glutamyl carboxylation of glutamic acid residues on clotting Factors II (prothrombin), VII, IX, and X, and anticoagulant regulatory Proteins C and S, rendering them biologically inactive.
Rp.: Tab. Warfarini 0.005 N. 50 D.t.d. N. 50 S. Orally, 1 tablet (5 mg) once daily in the evening at 18:00; adjust dose according to INR (target INR 2.0-3.0; 2.5-3.5 for mechanical valves).
Clinical Dosage Regimen: VTE treatment, AFib, Mechanical Heart Valves: start 5 mg daily, check INR on day 3 and adjust. 36-72 hour lag until full antithrombotic effect.
Key Examination Pearls: Inhibits VKORC1 (factors II, VII, IX, X, Protein C & S). 99% albumin bound, CYP2C9 metabolism. Mandatory overlap with Heparin for 5 days. CONTRAINDICATED in pregnancy (teratogenic). Antidote: Vitamin K1 (Phytomenadione) + 4-factor PCC.
#20 Clopidogrel (Clopidogrelum)
Official Forms: Tablets / Capsules 0.075 (75 mg)
PDF 1 (#20) - Antiplatelet / P2Y12 Receptor Antagonist
⚡ Mechanism of Action (MOA):
Thienopyridine prodrug bioactivated in the liver by CYP2C19 into an active thiol metabolite -> irreversibly alkylates platelet P2Y12 ADP receptors -> prevents ADP-mediated activation of the GPIIb/IIIa integrin complex, permanently suppressing platelet activation and fibrinogen cross-linking for the 7-10 day platelet lifespan.
Rp.: Tab. Clopidogreli 0.075 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (75 mg) once daily, irrespective of meals.
Clinical Dosage Regimen: Secondary prevention of Atherothrombosis (post-stroke, post-MI, PAD): 75 mg daily. ACS / Post-PCI Stenting: 300-600 mg loading dose oral, followed by 75 mg daily in combination with Aspirin (DAPT) for 6-12 months.
Key Examination Pearls: Thienopyridine prodrug; irreversibly blocks platelet P2Y12 ADP receptors. Requires two-step hepatic bioactivation via CYP2C19. Omeprazole inhibits CYP2C19 and reduces efficacy (use Pantoprazole).
#21 Acenocoumarol (Acenocoumarolum / Sintrom)
Official Forms: Tablets 0.002 (2 mg)
PDF 1 (#21) - Indirect Anticoagulant (Vitamin K Antagonist)
⚡ Mechanism of Action (MOA):
Synthetic 4-hydroxycoumarin derivative; competitively inhibits VKORC1, blocking the post-translational gamma-carboxylation of Vitamin K-dependent coagulation factors (II, VII, IX, X), producing oral anticoagulation with a shorter half-life (~8-11 hours) than warfarin.
Rp.: Tab. Acenocoumaroli 0.002 N. 30 D.t.d. N. 30 S. Orally, 1-2 tablets (2-4 mg) once daily in the evening; adjust dose strictly according to INR (target 2.0-3.0).
Clinical Dosage Regimen: Thromboembolism prophylaxis and treatment, Atrial Fibrillation: initial 4 mg day 1, 2-3 mg day 2, maintenance usually 1-4 mg daily based on INR.
Key Examination Pearls: Shorter half-life (~8-11 hours) than Warfarin (~40 hours), offering quicker reversal upon discontinuation and faster INR normalization.
#22 Acetylsalicylic acid (Acidum acetylsalicylicum / Aspirin)
Official Forms: Tablets 0.075 (75 mg); 0.1 (100 mg); 0.15 (150 mg); 0.324 (324 mg); Capsules 0.075
PDF 1 (#22) - Antiplatelet / Irreversible COX-1 Inhibitor
⚡ Mechanism of Action (MOA):
Irreversibly acetylates Serine 529 residue of platelet cyclooxygenase-1 (COX-1) -> permanently shuts down the conversion of arachidonic acid to Thromboxane A2 (TXA2, a potent inducer of platelet aggregation and vasoconstriction) for the entire 7-10 day platelet lifespan.
Rp.: Tab. Acidi acetylsalicylici 0.1 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (100 mg) once daily after lunch.
Clinical Dosage Regimen: Cardiovascular secondary prevention (post-MI, stable angina, stroke/TIA): 75-100 mg daily. Acute Coronary Syndrome (STEMI/NSTEMI): 150-325 mg non-enteric chewed immediately.
Key Examination Pearls: Irreversibly acetylates platelet COX-1, eliminating TXA2 production for the 7-10 day platelet lifespan. Low doses (75-100 mg) spare vascular endothelial PGI2 (prostacyclin).
#23 Alteplase (Alteplasum / rt-PA)
Official Forms: Powder 0.05 (50 mg) in vials with solvent
PDF 1 (#23) - Fibrinolytic / Recombinant Tissue Plasminogen Activator
⚡ Mechanism of Action (MOA):
Recombinant human tissue-type plasminogen activator (serine protease); binds selectively to fibrin on the surface of the thrombus and enzymatically cleaves the Arg560-Val561 bond of plasminogen -> converts plasminogen to active plasmin -> plasmin degrades the cross-linked fibrin meshwork, dissolving the intravascular clot.
Rp.: Alteplasi 0.05 D.t.d. N. 2 in phialis cum solubili S. For IV infusion: dissolve 100 mg in sterile water; administer 15 mg IV bolus, then 50 mg over 30 min, then 35 mg over 60 min (accelerated protocol for acute STEMI within 12 hours).
Clinical Dosage Regimen: STEMI: 100 mg accelerated IV over 90 min. Acute Ischemic Stroke: 0.9 mg/kg (max 90 mg) IV over 60 min (10% bolus over 1 min), within 4.5 hours of symptom onset. Massive PE: 100 mg IV over 2 hours.
Key Examination Pearls: Fibrin-specific serine protease; binds fibrin clot and converts plasminogen to plasmin locally. Major risk: intracranial hemorrhage. Antidote: Tranexamic acid / Aminocaproic acid.
#24 Aminocaproic acid (Acidum aminocaproicum)
Official Forms: Solution 5% - 500 ml in vials
PDF 1 (#24) - Antifibrinolytic / Hemostatic Agent
⚡ Mechanism of Action (MOA):
Synthetic lysine analog; competitively binds to the lysine-binding sites of plasminogen and active plasmin -> prevents plasminogen activation and blocks plasmin from binding to and degrading fibrin, completely preserving fibrin clot architecture and arresting hyperfibrinolytic hemorrhage.
Rp.: Sol. Acidi aminocaproici 5% - 500 ml D.t.d. N. 2 in phialis S. For IV drip infusion: infuse 100 ml (5 g) over the first hour, then continuous infusion of 20 ml (1 g)/hour until bleeding is controlled.
Clinical Dosage Regimen: Severe hyperfibrinolytic bleeding, Fibrinolytic overdose (Alteplase, Streptokinase), surgical bleeding (cardiac, prostatic, dental in hemophilia): 4-5 g IV over 1h, then 1 g/h.
Key Examination Pearls: Lysine analogue; competitively blocks plasminogen activation and plasmin binding to fibrin. Contraindicated in DIC without heparin and upper urinary tract bleeding (ureteral clot obstruction).
#25 Protamine sulfate (Protamini sulfas)
Official Forms: Solution 1% - 10 ml ampoules (100 mg/10 ml)
PDF 1 (#25) - Specific Heparin Antidote
⚡ Mechanism of Action (MOA):
Strongly basic, low-molecular-weight polycationic peptide rich in arginine residues -> electrostatically binds with high affinity to strongly acidic, polyanionic unfractionated heparin -> forms an inactive, stable, non-toxic salt complex that completely neutralizes heparin's anticoagulant properties.
Rp.: Sol. Protamini sulfatis 1% - 10 ml D.t.d. N. 5 in ampullis S. For IV injection: administer 5 ml (50 mg) slow IV injection over 10-15 minutes (1 mg neutralizes ~100 IU unfractionated heparin).
Clinical Dosage Regimen: Severe heparin-induced bleeding or emergency reversal post-cardiopulmonary bypass: calculate dose based on heparin remaining (1 mg protamine per 100 IU heparin). Max 50 mg in any 10-minute period.
Key Examination Pearls: Polycationic peptide forms an inactive salt complex with polyanionic heparin. Rapid injection causes catastrophic anaphylactoid hypotension and bradycardia! Overdose has anticoagulant activity.
#26 Phytomenadione (Phytomenadionum / Vitamin K1)
Official Forms: Solution 1% - 1 ml (10 mg) ampoules
PDF 1 (#26) - Coagulant / Vitamin K Antagonist Antidote
⚡ Mechanism of Action (MOA):
Lipid-soluble naphthoquinone; serves as an essential obligate cofactor for hepatic microsomal gamma-glutamyl carboxylase -> converts glutamate residues on descarboxy-prothrombin into gamma-carboxyglutamate (Gla) on clotting Factors II, VII, IX, and X, directly overcoming competitive VKORC1 inhibition by warfarin.
Rp.: Sol. Phytomenadioni 1% - 1 ml D.t.d. N. 5 in ampullis S. For IV injection: dilute 1 ml (10 mg) in 50 ml of 5% glucose or 0.9% NaCl, administer by slow IV infusion over 20-30 minutes.
Clinical Dosage Regimen: Major bleeding due to Warfarin overdose: 5-10 mg slow IV (with 4-factor PCC). Asymptomatic high INR (>10): 2.5-5 mg oral. Hemorrhagic disease of newborn: 1 mg IM/slow IV at birth.
Key Examination Pearls: Fat-soluble vitamin required for gamma-glutamyl carboxylase activation (Factors II, VII, IX, X). Full effect takes 6-24 hours. Rapid IV push can cause severe anaphylactoid shock.
#27 Tirofiban (Tirofibanum)
Official Forms: Solution 0.025% - 50 ml in vials (concentrate 12.5 mg/50 ml)
PDF 1 (#27) - Antiplatelet / GPIIb/IIIa Receptor Antagonist
⚡ Mechanism of Action (MOA):
Highly selective non-peptide reversible antagonist of the platelet glycoprotein IIb/IIIa (GPIIb/IIIa / integrin alpha-IIb-beta-3) receptor -> competitively prevents fibrinogen and von Willebrand factor from binding to activated platelets, blocking the final common pathway of platelet aggregation and thrombus formation.
Rp.: Sol. Tirofibani 0.025% - 50 ml D.t.d. N. 2 in phialis S. For IV infusion: initial bolus 25 mcg/kg IV over 3 minutes, followed by continuous maintenance infusion 0.15 mcg/kg/min for up to 48 hours.
Clinical Dosage Regimen: High-risk NSTE-ACS undergoing early Percutaneous Coronary Intervention (PCI): 25 mcg/kg bolus over 3 min, then 0.15 mcg/kg/min maintenance.
Key Examination Pearls: Non-peptide reversible antagonist of the glycoprotein IIb/IIIa receptor; prevents fibrinogen cross-linking of activated platelets (final common pathway of aggregation).
#28 Etamsylate (Etamsylatum / Dicynone)
Official Forms: Solution 12.5% - 2 ml (250 mg) ampoules; Tablets 0.25 (250 mg)
PDF 1 (#28) - Hemostatic / Aggregant & Angioprotector
⚡ Mechanism of Action (MOA):
Synthetic hemostatic and angioprotector; enhances thromboplastin (Factor III) formation and platelet adhesiveness to damaged subendothelium via membrane mucopolysaccharide stabilization; increases capillary resistance and reduces capillary fragility without affecting systemic coagulation cascade parameters (PT, aPTT) or inducing thrombosis.
Rp.: Sol. Etamsylati 12.5% - 2 ml D.t.d. N. 10 in ampullis S. For IM/IV injection: 2-4 ml (250-500 mg) IV or IM 2-3 times daily. Rp.: Tab. Etamsylati 0.25 N. 30 D.t.d. N. 30 S. Orally, 1-2 tablets (250-500 mg) 3-4 times daily with meals.
Clinical Dosage Regimen: Capillary bleeding (epistaxis, menorrhagia, post-tonsillectomy, dental extractions, diabetic microangiopathy, neonatal intraventricular hemorrhage prophylaxis): 250-500 mg IV/IM or orally TID-QID.
Key Examination Pearls: Increases platelet adhesion (Factor III activation) and capillary wall resistance without hypercoagulability or thrombosis risk. Clotting parameters (PT, aPTT) remain unchanged.
#29 Methyldopa (Methyldopum / Dopegyt)
Official Forms: Tablets 0.25 (250 mg)
PDF 2 (#1) - Centrally Acting Antihypertensive (Alpha-2 Agonist)
⚡ Mechanism of Action (MOA):
Centrally acting antihypertensive prodrug; transported across the blood-brain barrier and decarboxylated in adrenergic neurons to alpha-methylnorepinephrine -> selectively stimulates central presynaptic Alpha-2 adrenoreceptors in the medullary vasomotor center (NTS/RVLM) -> suppresses central sympathetic outflow to the heart, blood vessels, and kidneys, lowering peripheral vascular resistance and BP while preserving placental perfusion.
Rp.: Tab. Methyldopi 0.25 N. 50 D.t.d. N. 50 S. Orally, 1 tablet (250 mg) 2-3 times daily, maximum 2000 mg daily.
Clinical Dosage Regimen: Chronic Arterial Hypertension in Pregnancy (First-line): 250 mg BID-TID, titrated weekly up to 2 g/day.
Key Examination Pearls: Prodrug converted to alpha-methylnorepinephrine in adrenergic neurons; stimulates central presynaptic alpha-2 receptors, decreasing sympathetic outflow. Adverse effects: Coombs-positive hemolytic anemia, sedation, hepatitis, depression.
#30 Moxonidine (Moxonidinum)
Official Forms: Tablets 0.0002 (0.2 mg); 0.0003 (0.3 mg); 0.0004 (0.4 mg)
PDF 2 (#2) - Selective Imidazoline I1-Receptor Agonist
⚡ Mechanism of Action (MOA):
Highly selective agonist of central Imidazoline I1-receptors in the rostral ventrolateral medulla (RVLM), with weak Alpha-2 affinity -> reduces central sympathetic nervous system outflow to the heart and peripheral vasculature -> lowers systemic vascular resistance, drops blood pressure, and improves peripheral insulin sensitivity with minimal sedation or dry mouth.
Rp.: Tab. Moxonidini 0.0002 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (0.2 mg) once daily in the morning, max 0.6 mg daily.
Clinical Dosage Regimen: Essential arterial hypertension with metabolic syndrome / overweight: start 0.2 mg daily, titrate after 3 weeks to 0.4 mg daily (single or divided dose).
Key Examination Pearls: Selective agonist of I1-imidazoline receptors in the rostral ventrolateral medulla (RVLM). Reduces central sympathetic tone with significantly less dry mouth and sedation than clonidine. Improves insulin sensitivity.
#31 Propranolol (Propranololum / Anaprilin)
Official Forms: Tablets 0.01 (10 mg); 0.04 (40 mg); 0.1 (100 mg)
PDF 2 (#3) - Non-selective Beta-1 & Beta-2 Blocker
⚡ Mechanism of Action (MOA):
Non-selective competitive antagonist of Beta-1 and Beta-2 adrenoreceptors -> blocks cardiac Beta-1 receptors (decreases heart rate, contractility, and cardiac output) and renal Beta-1 receptors (suppresses renin secretion); blocks peripheral Beta-2 receptors (may precipitate bronchospasm in asthma and unopposed alpha-1 vasoconstriction in vasospastic angina).
Rp.: Tab. Propranololi 0.04 N. 50 D.t.d. N. 50 S. Orally, 1 tablet (40 mg) 2-3 times daily before meals.
Clinical Dosage Regimen: Sympathoadrenal arrhythmias, Thyrotoxicosis, Essential tremor, Migraine prophylaxis, Portal hypertension: 40-80 mg 2-3 times daily.
Key Examination Pearls: Non-selective. Highly lipophilic, crosses blood-brain barrier (vivid dreams, depression). STRICTLY CONTRAINDICATED in asthma, COPD, and Prinzmetal vasospastic angina!
#32 Nebivolol (Nebivololum)
Official Forms: Tablets 0.005 (5 mg)
PDF 2 (#6) - Highly Selective Beta-1 Blocker with NO Vasodilation
⚡ Mechanism of Action (MOA):
Third-generation Beta-blocker with dual mechanism: possesses the highest cardioselectivity for Beta-1 adrenoreceptors (beta-1/beta-2 ratio ~321:1) AND directly stimulates endothelial Beta-3 receptors to activate endothelial nitric oxide synthase (eNOS) -> releases endogenous Nitric Oxide (NO) -> produces systemic vasodilation, reduces afterload, and preserves erectile function.
Rp.: Tab. Nebivololi 0.005 N. 28 D.t.d. N. 28 S. Orally, 1 tablet (5 mg) once daily at the same time each day.
Clinical Dosage Regimen: Essential Hypertension & Chronic Heart Failure in elderly (>70 yrs): 5 mg once daily. CHF: start at 1.25 mg daily and titrate.
Key Examination Pearls: Dual mechanism: Highest beta-1 selectivity + stimulates endothelial beta-3 receptors causing Nitric Oxide (NO) release. Results in vasodilation, preserved erectile function, and neutral metabolic profile.
#33 Carvedilol (Carvedilolum)
Official Forms: Tablets 0.00625 (6.25 mg); 0.0125 (12.5 mg); 0.025 (25 mg)
PDF 2 (#7) - Non-selective Beta + Alpha-1 Blocker with Antioxidant Action
⚡ Mechanism of Action (MOA):
Third-generation non-selective Beta-blocker (blocks Beta-1 and Beta-2) with competitive Alpha-1 adrenoreceptor blocking properties (beta-to-alpha blockade ratio ~10:1) and direct antioxidant actions -> Alpha-1 blockade dilates systemic resistance arterioles (reducing afterload), while Beta-blockade prevents reflex tachycardia, protects cardiomyocytes from catecholamine toxicity, and reduces mortality in HFrEF.
Rp.: Tab. Carvediloli 0.0125 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (12.5 mg) twice daily with meals.
Clinical Dosage Regimen: Chronic Heart Failure (HFrEF): start 3.125 mg BID with food, double every 2 weeks to target 25-50 mg BID. Hypertension: 12.5 mg daily for 2 days, then 25 mg daily.
Key Examination Pearls: Blocks beta-1, beta-2, and alpha-1 receptors (ratio ~10:1 beta to alpha). Causes peripheral vasodilation (reduces afterload) and possesses potent antioxidant properties. Proven mortality reduction in HF.
#34 Lercanidipine (Lercanidipinum)
Official Forms: Tablets 0.01 (10 mg); 0.02 (20 mg)
PDF 2 (#9) - 3rd Generation DHP Calcium Channel Blocker
⚡ Mechanism of Action (MOA):
Third-generation dihydropyridine calcium channel blocker with extreme lipophilicity; partitions into the lipid bilayer of vascular smooth muscle cell membranes, providing slow, smooth-onset and sustained 24-hour blockade of L-type Ca2+ channels -> causes gradual peripheral vasodilation with minimal reflex sympathetic tachycardia and a significantly lower incidence of pretibial ankle edema.
Rp.: Tab. Lercanidipini 0.01 N. 28 D.t.d. N. 28 S. Orally, 1 tablet (10 mg) once daily in the morning, at least 15 minutes before breakfast.
Clinical Dosage Regimen: Mild to Moderate Essential Arterial Hypertension (especially in elderly): start 10 mg once daily, increase if needed to 20 mg daily after 2 weeks.
Key Examination Pearls: Extremely lipophilic; accumulates in the vascular smooth muscle cell membrane lipid bilayer, providing gradual onset and long 24-hour duration. Much lower incidence of pretibial ankle edema and reflex tachycardia than older DHPs.
#35 Losartan (Losartanum)
Official Forms: Tablets 0.025 (25 mg); 0.05 (50 mg); 0.1 (100 mg)
PDF 2 (#12) - Angiotensin II Receptor Blocker (ARB / AT1 Blocker)
⚡ Mechanism of Action (MOA):
Competitive, selective antagonist of the Angiotensin II Type 1 (AT1) receptor; bioactivated by CYP2C9/3A4 to EXP3174 (which is 10-40x more potent) -> blocks Ang II-mediated arteriolar vasoconstriction, aldosterone synthesis, sympathetic facilitation, and cardiac hypertrophy; uniquely inhibits renal tubular URAT1 transporters, promoting urinary uric acid excretion.
Rp.: Tab. Losartani 0.05 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (50 mg) once daily, irrespective of food.
Clinical Dosage Regimen: Hypertension, Diabetic Nephropathy in Type 2 DM, Stroke prevention: 50 mg once daily, can increase to 100 mg daily.
Key Examination Pearls: Competitive AT1 receptor blocker. Prodrug converted to active 5-carboxylic acid metabolite (EXP3174), which is 10-40x more potent. Has unique uricosuric effect (lowers serum uric acid, great in gout!). NO bradykinin cough.
#36 Epinephrine / Adrenaline (Epinephrinum)
Official Forms: Solution 0.18% - 1 ml ampoules (1.8 mg/ml epinephrine tartrate ~ 1 mg/ml base = 1:1000)
PDF 2 (#13) - Non-selective Alpha & Beta Adrenomimetic
⚡ Mechanism of Action (MOA):
Potent, non-selective agonist of Alpha-1, Alpha-2, Beta-1, Beta-2, and Beta-3 adrenoreceptors -> Alpha-1 stimulation reverses systemic vasodilation and mucosal edema; Beta-1 stimulation enhances myocardial contractility and heart rate; Beta-2 stimulation relaxes bronchial smooth muscle and inhibits histamine/leukotriene mediator release from mast cells (first-line in anaphylaxis).
Rp.: Sol. Epinephrini 0.18% - 1 ml D.t.d. N. 10 in ampullis S. For IM injection: administer 0.3-0.5 ml (0.3-0.5 mg) IM into anterolateral thigh immediately for anaphylactic shock; repeat every 5-15 min PRN. For Cardiac Arrest (ACLS): 1 ml (1 mg) IV bolus every 3-5 minutes followed by 20 ml flush.
Clinical Dosage Regimen: Anaphylactic shock: 0.3-0.5 mg IM. Cardiac arrest (VF/pVT, asystole, PEA): 1 mg IV every 3-5 min. Severe croup / broncho-obstruction: nebulized 0.5 ml/kg.
Key Examination Pearls: Potent stimulant of alpha-1 (vasoconstriction), beta-1 (inotrope & chronotrope), and beta-2 (bronchodilation and mast cell stabilization). Drug of absolute choice in anaphylaxis!
#37 Norepinephrine / Noradrenaline (Norepinephrinum)
Official Forms: Solution 0.1% - 1 ml; 2 ml; 4 ml; 8 ml; 10 ml ampoules (1 mg/ml)
PDF 2 (#14) - Potent Alpha-1, Alpha-2 & Beta-1 Adrenomimetic
⚡ Mechanism of Action (MOA):
Potent agonist of Alpha-1 and Alpha-2 adrenoreceptors with moderate Beta-1 cardiac stimulation and negligible Beta-2 activity -> induces intense arterial and venous vasoconstriction -> elevates systemic vascular resistance (SVR) and mean arterial pressure (MAP) while supporting cardiac stroke volume with minimal excessive tachycardia (first-line vasopressor in septic and vasodilatory shock).
Rp.: Sol. Norepinephrini 0.1% - 4 ml D.t.d. N. 5 in ampullis S. For IV infusion: dilute 4 ml (4 mg) in 250-500 ml of 5% glucose; infuse via central line at initial rate 0.05-0.5 mcg/kg/min, titrate to MAP >= 65 mmHg.
Clinical Dosage Regimen: Septic Shock, Vasodilatory / Vasoplegic Shock, Cardiogenic Shock with profound hypotension: initial 2-4 mcg/min, titrate to mean arterial pressure >= 65 mmHg.
Key Examination Pearls: First-line vasopressor in septic shock. Intense alpha-1 vasoconstriction with moderate beta-1 cardiac stimulation; minimal beta-2 effect. Must be infused via central venous catheter (extravasation causes tissue necrosis; antidote: phentolamine).
#38 Phenylephrine (Phenylephrinum / Mesaton)
Official Forms: Solution 1% - 1 ml ampoules (10 mg/ml)
PDF 2 (#15) - Pure Selective Alpha-1 Adrenomimetic
⚡ Mechanism of Action (MOA):
Pure, selective Alpha-1 adrenoreceptor agonist with zero direct beta-adrenergic activity -> directly stimulates vascular smooth muscle Gq-protein coupled Alpha-1 receptors -> activates phospholipase C, generating IP3 and DAG -> releases intracellular Ca2+, causing intense systemic arteriolar vasoconstriction, elevating SVR and BP, and triggering reflex vagal bradycardia.
Rp.: Sol. Phenylephrini 1% - 1 ml D.t.d. N. 10 in ampullis S. For IV injection: dilute 0.1-0.5 ml in 20 ml 0.9% NaCl, inject slowly IV over 2-3 minutes; or continuous infusion 0.5-2 mcg/kg/min.
Clinical Dosage Regimen: Hypotension during spinal/epidural anesthesia, Vasomotor collapse / acute hypotension: 0.1-0.5 mg slow IV bolus or 20-100 mcg/min infusion. Paroxysmal SVT (via reflex vagal stimulation).
Key Examination Pearls: Pure alpha-1 agonist with no direct beta-adrenergic action. Raises SVR and systolic/diastolic BP, triggering reflex bradycardia. Useful when tachycardia limits other vasopressors.
#39 Dopamine (Dopaminum)
Official Forms: Solution 0.5% - 5 ml (25 mg); Solution 4% - 5 ml (200 mg) ampoules
PDF 2 (#16) - Dose-Dependent Dopaminergic & Adrenergic Agonist
⚡ Mechanism of Action (MOA):
Endogenous catecholamine precursor with dose-dependent receptor selectivity: Low dose (0.5-2 mcg/kg/min) stimulates vascular D1 receptors (adenylyl cyclase activation -> renal and mesenteric vasodilation, increasing diuresis); Medium dose (2-10 mcg/kg/min) stimulates cardiac Beta-1 receptors (increases contractility, HR, and cardiac output); High dose (>10 mcg/kg/min) stimulates vascular Alpha-1 receptors (intense systemic vasoconstriction, elevating SVR and BP).
Rp.: Sol. Dopamini 4% - 5 ml D.t.d. N. 5 in ampullis S. For IV drip infusion: dilute 5 ml (200 mg) in 250 ml of 5% glucose or 0.9% NaCl; infuse at rate 2-20 mcg/kg/min adjusted to hemodynamics.
Clinical Dosage Regimen: Cardiogenic shock / Hypotension with bradycardia: Low dose (0.5-3 mcg/kg/min) = D1 receptors (renal/mesenteric vasodilation); Medium dose (3-10 mcg/kg/min) = Beta-1 receptors (positive inotrope); High dose (>10 mcg/kg/min) = Alpha-1 receptors (systemic vasoconstriction).
Key Examination Pearls: Risk of tachyarrhythmias and excessive myocardial oxygen consumption. Second-line to Norepinephrine in septic shock.
#40 Sodium caffeine benzoate (Coffeini-natrii benzoas)
Official Forms: Infusion / Oral solution 2% - 1 ml; 3 ml ampoules; Tablets 0.1; 0.2
PDF 2 (#17) - Central Analeptic & Psychostimulant
⚡ Mechanism of Action (MOA):
Central analeptic and psychostimulant; non-selectively antagonizes inhibitory adenosine A1 and A2A receptors in the brain and inhibits phosphodiesterase (PDE) -> directly stimulates medullary vasomotor and respiratory centers, increases cerebral vascular tone, elevates sympathetic tone, and enhances myocardial contractility.
Rp.: Sol. Coffeini-natrii benzoatis 2% - 1 ml D.t.d. N. 10 in ampullis S. For SC or IM injection: 1-2 ml 1-2 times daily. Rp.: Tab. Coffeini-natrii benzoatis 0.1 N. 20 D.t.d. N. 20 S. Orally, 1 tablet (100 mg) 2-3 times daily.
Clinical Dosage Regimen: Acute and chronic hypotension, collapse, infectious asthenia, CNS depression: 100-200 mg oral or SC/IM.
Key Examination Pearls: Non-selective adenosine receptor antagonist (A1 and A2A) and phosphodiesterase (PDE) inhibitor. Directly stimulates medullary vasomotor and respiratory centers, increases cerebral vascular tone and alertness.
#41 Sacubitril + Valsartan (Entresto / ARNI)
Official Forms: Tablets 0.024/0.026 (24/26 mg = 50 mg); 0.049/0.051 (49/51 mg = 100 mg); 0.097/0.103 (97/103 mg = 200 mg)
PDF 2 (#18) - Angiotensin Receptor-Neprilysin Inhibitor (ARNI)
⚡ Mechanism of Action (MOA):
Dual Angiotensin Receptor-Neprilysin Inhibitor: Sacubitril prodrug is metabolized to LBQ657, which inhibits neprilysin (neutral endopeptidase), preventing the enzymatic degradation of natriuretic peptides (ANP, BNP, CNP) and bradykinin -> enhances natriuresis, diuresis, and vasodilation; Valsartan selectively blocks the AT1 receptor, preventing Ang II-mediated vasoconstriction, sodium retention, and myocardial remodeling.
Rp.: Tab. Sacubitril / Valsartan 0.049 / 0.051 N. 56 D.t.d. N. 56 S. Orally, 1 tablet (49/51 mg) twice daily with or without food; titrate to target 97/103 mg BID after 2-4 weeks.
Clinical Dosage Regimen: Chronic Heart Failure with reduced ejection fraction (HFrEF NYHA II-IV): start 24/26 mg or 49/51 mg BID, titrate every 2-4 weeks to target 97/103 mg BID.
Key Examination Pearls: Sacubitril inhibits neprilysin, preventing breakdown of natriuretic peptides (ANP, BNP, CNP, bradykinin), promoting natriuresis and vasodilation. Valsartan blocks AT1 receptor. MANDATORY 36-hour washout when switching from an ACE inhibitor to prevent fatal angioedema!
#42 Furosemide (Furosemidum / Lasix)
Official Forms: Tablets 0.04 (40 mg); Solution 1% - 2 ml (20 mg) ampoules
PDF 2 (#19) - High-Ceiling Loop Diuretic
⚡ Mechanism of Action (MOA):
High-ceiling loop diuretic; reversibly binds to the chloride-binding site of the luminal Na+/K+/2Cl- cotransporter (NKCC2) in the Thick Ascending Limb of the Loop of Henle -> inhibits reabsorption of Na+, K+, and 2Cl- -> abolishes the hypertonic medullary osmotic gradient, causing massive excretion of Na+, Cl-, K+, Ca2+, and Mg2+ (20-25% filtered Na+ excreted) and reducing extracellular fluid volume and venous return.
Rp.: Tab. Furosemidi 0.04 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (40 mg) once daily in the morning on an empty stomach. Rp.: Sol. Furosemidi 1% - 2 ml D.t.d. N. 10 in ampullis S. For IV injection: 2-4 ml (20-40 mg) slow IV over 2 minutes (for acute pulmonary edema or hypertensive crisis).
Clinical Dosage Regimen: Acute pulmonary edema: 40-80 mg IV bolus. Chronic Heart Failure / Cirrhotic ascites / Nephrotic syndrome: 20-80 mg oral daily. Hypertensive crisis: 40-80 mg IV.
Key Examination Pearls: Inhibits luminal Na+/K+/2Cl- cotransporter (NKCC2) in thick ascending limb of Henle. High potency (excretes 20-25% filtered Na+). Wastes Na+, K+, Cl-, Ca2+, Mg2+ ('Loops lose Calcium'). Adverse effects: hypokalemic metabolic alkalosis, ototoxicity, hyperuricemia.
#43 Spironolactone (Spironolactonum / Verospiron)
Official Forms: Tablets 0.025 (25 mg); 0.05 (50 mg); 0.1 (100 mg); Capsules 0.05
PDF 2 (#20) - Competitive Aldosterone Receptor Antagonist (MRA)
⚡ Mechanism of Action (MOA):
Synthetic steroid that acts as a competitive antagonist of intracellular mineralocorticoid (aldosterone) receptors in the principal cells of the late distal convoluted tubule and cortical collecting duct -> blocks aldosterone-induced gene expression of apical ENaC channels and basolateral Na+/K+-ATPase pumps -> promotes moderate natriuresis and water loss while completely sparing potassium and hydrogen ions (prevents hypokalemia and myocardial interstitial fibrosis).
Rp.: Tab. Spironolactoni 0.025 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (25 mg) once daily with morning breakfast.
Clinical Dosage Regimen: Chronic Heart Failure (HFrEF NYHA II-IV): 25-50 mg daily. Resistant Hypertension: 25-50 mg daily. Primary hyperaldosteronism (Conn's) & Cirrhotic ascites: 100-400 mg daily.
Key Examination Pearls: Competitive mineralocorticoid receptor antagonist in cortical collecting tubule; spares K+ and H+, excretes Na+ and water. Prevents cardiac fibrosis and remodeling. Adverse effects: hyperkalemia, gynecomastia, menstrual irregularities (switch to Eplerenone).
#44 Indapamide (Indapamidum)
Official Forms: Tablets 0.0015 (1.5 mg) [retard]; 0.0025 (2.5 mg); Capsules 0.0025
PDF 2 (#21) - Thiazide-like Diuretic & Vasodilator
⚡ Mechanism of Action (MOA):
Thiazide-like diuretic and direct vasodilator with dual action: (1) Inhibits the luminal Na+/Cl- cotransporter (NCC) in the early distal convoluted tubule, producing mild-to-moderate natriuresis and diuresis; (2) Directly reduces vascular smooth muscle contractility and reactivity by blocking trans-sarcolemmal Ca2+ influx and stimulating local vasodilatory prostacyclin (PGI2) synthesis.
Rp.: Tab. Indapamidi retard 0.0015 N. 30 D.t.d. N. 30 S. Orally, 1 tablet (1.5 mg) once daily in the morning.
Clinical Dosage Regimen: Essential Arterial Hypertension (First-line): 1.5 mg sustained-release or 2.5 mg immediate-release once daily.
Key Examination Pearls: Dual mechanism: Mild natriuresis via NCC cotransporter inhibition in early distal tubule + direct arteriolar vasodilation by blocking vascular smooth muscle calcium entry and enhancing prostacyclin synthesis. Metabolically neutral (does not alter glucose or lipid profiles).

🧠 Active Recall Spaced Repetition Flashcards

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Heart Failure
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📝 Faculty Mock Exam Simulator

15 clinical vignette questions modeled after the Official Faculty Department of Clinical Pharmacology exam papers.

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Question 1: A 68-year-old patient with congestive heart failure and atrial fibrillation stabilized on Digoxin presents with nausea, yellow-tinted vision (xanthopsia), and frequent premature ventricular contractions. Serum K+ is 3.1 mmol/L. What is the most appropriate initial pharmacological intervention?
Rationale: Discontinuing digitalis and correcting hypokalemia with IV/oral Potassium Chloride is the cornerstone of therapy. Hypokalemia increases digoxin binding to Na+/K+ ATPase and aggravates toxicity. IV Calcium is strictly contraindicated (triggers 'stone heart' arrest), Quinidine displaces digoxin and doubles its toxicity, and electrical cardioversion can trigger refractory VF.
Question 2: A 55-year-old male with a history of acute myocardial infarction 6 months ago develops frequent runs of non-sustained ventricular tachycardia. Which of the following antiarrhythmic agents is STRICTLY CONTRAINDICATED due to demonstrated excess mortality in clinical trials?
Rationale: Flecainide (Class IC) was proven in the landmark CAST (Cardiac Arrhythmia Suppression Trial) study to dramatically increase mortality and sudden cardiac death when used in patients with prior myocardial infarction and structural heart disease. Lidocaine, Amiodarone, and Metoprolol are safe or beneficial post-MI.
Question 3: A 32-year-old woman presents with sudden-onset palpitations. The ECG confirms Paroxysmal Supraventricular Tachycardia (AVNRT) at a rate of 190 bpm. Vagal maneuvers fail. What is the pharmacological drug of choice for acute termination?
Rationale: Adenosine administered as a rapid IV bolus (6 mg then 12 mg) into a large peripheral vein followed by a saline flush is the first-line drug of choice for acute termination of AVNRT/AVRT. It causes transient profound AV nodal block with an ultra-short half-life (<10 seconds).
Question 4: A 48-year-old woman with a history of severe nocturnal chest pain with transient ST-segment elevation is diagnosed with Vasospastic (Prinzmetal) Angina. Which medication is STRICTLY CONTRAINDICATED?
Rationale: Non-selective Beta-blockers like Propranolol (and beta-blockers in general) are strictly contraindicated in vasospastic angina. Blocking Beta-2 mediated coronary vasodilation leaves Alpha-1 adrenergic vasoconstriction unopposed, precipitating severe, life-threatening coronary vasospasm. CCBs and Nitrates are the drugs of choice.
Question 5: A 42-year-old patient who underwent mechanical prosthetic mitral valve replacement requires long-term anticoagulation. Which of the following anticoagulants is the ONLY recommended drug of choice?
Rationale: Warfarin (Vitamin K antagonist, target INR 2.5-3.5) is the ONLY approved anticoagulant for mechanical prosthetic heart valves. The RE-ALIGN trial demonstrated that DOACs (Dabigatran, Rivaroxaban) are contraindicated due to significantly increased rates of valve thrombosis, stroke, and major bleeding.
Question 6: A 70-year-old patient on continuous Unfractionated Heparin for deep vein thrombosis develops severe epistaxis and bleeding from puncture sites. The aPTT is >150 seconds. What is the specific antidote to neutralize the anticoagulant effect?
Rationale: Protamine sulfate is a strongly basic polycationic peptide that rapidly binds to and neutralizes strongly acidic, polyanionic unfractionated heparin in a 1:1 ratio (1 mg protamine neutralizes ~100 IU heparin).
Question 7: A 30-year-old pregnant woman at 28 weeks gestation presents with a blood pressure of 165/105 mmHg. Which of the following antihypertensive medications is ABSOLUTELY CONTRAINDICATED?
Rationale: Enalapril (and all ACE inhibitors and ARBs) is strictly teratogenic and contraindicated during pregnancy, especially in the 2nd and 3rd trimesters, causing fetal renal dysgenesis, oligohydramnios, skull hypoplasia, and intrauterine fetal demise. Methyldopa, Labetalol, and Hydralazine are safe in pregnancy.
Question 8: A 58-year-old male with severe bilateral renal artery stenosis is mistakenly prescribed Lisinopril. Within 48 hours, his serum creatinine jumps from 1.2 mg/dL to 4.5 mg/dL with oliguria. What is the physiological mechanism responsible for this acute kidney injury?
Rationale: In bilateral renal artery stenosis, pre-glomerular perfusion pressure is low, and GFR is maintained by Angiotensin II-mediated constriction of the EFFERENT arteriole. ACE inhibitors eliminate Ang II, selectively dilating the efferent arteriole, which causes an immediate collapse in intraglomerular hydrostatic pressure and acute renal failure.
Question 9: A 45-year-old patient with confirmed pheochromocytoma is being prepared for adrenalectomy. Why must an Alpha-adrenoblocker be initiated before introducing a Beta-adrenoblocker?
Rationale: If a beta-blocker is administered alone without established alpha-blockade, it eliminates Beta-2 receptor-mediated peripheral vasodilation while massive circulating epinephrine and norepinephrine act unopposed on Alpha-1 receptors, precipitating severe malignant hypertension, acute pulmonary edema, or intracranial hemorrhage.
Question 10: Which of the following diuretic classes is uniquely indicated for the management of recurrent calcium nephrolithiasis and osteoporosis, and why?
Rationale: Thiazides ('Thiazides SAVE Calcium') enhance calcium reabsorption in the distal convoluted tubule, thereby lowering urinary calcium concentration (preventing calcium stone formation in idiopathic hypercalciuria) and increasing bone mineral density in osteoporosis. Loop diuretics waste calcium and worsen stones.
Question 11: A 24-year-old presents in the emergency department with severe bee sting anaphylaxis: stridor, facial angioedema, wheezing, and blood pressure of 70/40 mmHg. What is the immediate life-saving drug, dose, and route of administration?
Rationale: Intramuscular Epinephrine (0.3-0.5 mg of 1:1000) into the anterolateral thigh is the first-line treatment for anaphylaxis. It acts rapidly on Alpha-1 (reverses vasodilation/mucosal edema), Beta-1 (restores cardiac output), and Beta-2 (bronchodilation and halts mediator release from mast cells). Antihistamines and steroids are secondary adjuncts only.
Question 12: What is the recommended first-line vasopressor in Septic Shock after adequate crystalloid fluid resuscitation?
Rationale: Norepinephrine is the first-line vasopressor of choice in septic shock. Its potent Alpha-1 vasoconstrictor effect restores vascular resistance and MAP, with modest Beta-1 inotropic support, producing significantly fewer tachyarrhythmias and lower mortality than Dopamine.
Question 13: A patient with chronic heart failure who has been taking Enalapril is switched to Sacubitril/Valsartan (ARNI). What crucial guideline instruction must the physician follow to prevent life-threatening angioedema?
Rationale: A mandatory 36-hour washout interval is required between discontinuing an ACE inhibitor and initiating Sacubitril/Valsartan. Because both ACE and Neprilysin are responsible for the degradation of bradykinin, overlapping them leads to massive bradykinin accumulation and severe, potentially fatal angioedema.
Question 14: A 60-year-old patient receiving IV heparin for acute pulmonary embolism suddenly develops a 60% drop in platelet count on day 7, along with new pain and swelling in the left leg. What is the diagnosis and immediate management?
Rationale: This is Type II Heparin-Induced Thrombocytopenia (HIT), an immune-mediated thrombotic syndrome caused by anti-PF4/heparin antibodies. Management mandates IMMEDIATE cessation of all heparins (including LMWH, which cross-reacts 100%) and initiating a non-heparin direct thrombin inhibitor (Argatroban or Bivalirudin). Platelet transfusions are contraindicated because they fuel thrombosis.
Question 15: Which of the following antianginal medications causes a phenomenon known as 'coronary steal'?
Rationale: Dipyridamole is a potent arteriolar coronarodilation agent that selectively dilates resistance vessels in non-ischemic myocardial zones (which have normal autoregulatory reserve), diverting blood flow away from already maximally dilated ischemic vessels ('coronary steal') and aggravating angina.

⚡ High-Yield Rapid Cram Vault & Professor Exam Traps

Review these 20 minutes before walking into your exam hall to guarantee top marks!

🧠 High-Yield Mnemonics

Vaughan Williams Antiarrhythmic Classes
"No Bad Boy Keeps Clean (Na, Beta, K, Ca)"
Class I = Na+ channel blockers | Class II = Beta-blockers | Class III = K+ channel blockers | Class IV = Calcium channel blockers
Class I Antiarrhythmic Subclasses
"Double Quarter Pounder, Lettuce Mayo Pickle, Fries Please"
IA: Disopyramide, Quinidine, Procainamide (prolongs APD) | IB: Lidocaine, Mexiletine, Phenytoin (shortens APD) | IC: Flecainide, Propafenone (no APD effect)
Amiodarone Systemic Adverse Effects
"BITCHES Check TSH, PFT, LFT"
Bradycardia/Blue skin, Interstitial lung fibrosis, Thyroid (hypo/hyper), Corneal deposits, Hepatotoxicity, Eyes (optic neuropathy), Short QT -> actually Long QT!
Acute Pulmonary Edema / ADHF Management
"L M N O P"
Lasix (Furosemide IV) | Morphine IV | Nitrates (Nitroglycerin IV) | Oxygen | Position (upright with legs dangling)
Diuretic Calcium Balance Rule
"Loops LOSE Calcium, Thiazides TAKE (save) Calcium"
Loop diuretics (Furosemide) increase renal calcium excretion (treat hypercalcemia). Thiazides (Indapamide) decrease calcium excretion (treat calcium stones/osteoporosis).
Essential GDMT for Chronic HFrEF
"Fantastic Four"
1. ARNI (Sacubitril/Valsartan) or ACEi | 2. Beta-Blocker (Bisoprolol, Carvedilol, Metoprolol succinate) | 3. MRA (Spironolactone) | 4. SGLT2i (Dapagliflozin)
Vitamin K Dependent Clotting Factors
"1972 (Factors 10, 9, 7, 2) + Proteins C and S"
Factors II, VII, IX, X depend on hepatic gamma-glutamyl carboxylation by Vitamin K. Inhibited by Warfarin & Acenocoumarol.
Safe Antihypertensives in Pregnancy
"Better Mothers Love Nifedipine (BM-LN)"
Beta-blocker (Labetalol) | Methyldopa | Long-acting CCB (Nifedipine retard) | Hydralazine

⚠️ Top 10 Cardinal Professor Exam Traps

TRAP: IV Verapamil + IV Beta-Blocker
Why it's fatal: Dual profound suppression of SA/AV nodal conduction + profound negative inotropy triggers instant complete heart block, cardiogenic shock, and fatal asystole.
TRAP: Beta-Blockers in Prinzmetal (Vasospastic) Angina
Why it's fatal: Blocking Beta-2 receptors leaves coronary Alpha-1 receptors unopposed, precipitating catastrophic transmural coronary vasospasm and acute MI.
TRAP: Flecainide / Propafenone (Class IC) in Post-MI Patients
Why it's fatal: CAST trial proved Class IC drugs increase mortality and cause fatal ventricular proarrhythmias in ischemic and structurally diseased myocardium.
TRAP: ACE Inhibitors or ARBs in Bilateral Renal Artery Stenosis
Why it's fatal: Eliminates efferent arteriolar constriction, causing an immediate collapse of intraglomerular hydrostatic filtration pressure and acute renal failure.
TRAP: Beta-Blocker Monotherapy in Pheochromocytoma
Why it's fatal: Blocking Beta-2 vasodilation leaves massive circulating catecholamines acting unopposed on Alpha-1 receptors, causing fatal hypertensive crisis.
TRAP: Switching from ACEi to ARNI without 36-hour Washout
Why it's fatal: Both enzymes break down bradykinin; co-administration causes massive bradykinin surge and life-threatening angioedema.
TRAP: DOACs (Rivaroxaban, Dabigatran) in Mechanical Heart Valves
Why it's fatal: RE-ALIGN trial showed DOACs cause excess valve thrombosis and major bleeding compared to Warfarin. Warfarin is the only approved drug.
TRAP: IV Calcium in Digitalis Poisoning
Why it's fatal: Intracellular Ca2+ is already dangerously elevated. IV Calcium precipitates irreversible myofibrillar contraction ('stone heart') and fatal arrest.
TRAP: Platelet Transfusion in Heparin-Induced Thrombocytopenia (HIT)
Why it's fatal: Transfused platelets are immediately bound by anti-PF4/heparin antibodies, fueling catastrophic widespread thrombosis.
TRAP: Nitrates + Sildenafil / Tadalafil within 24-48 Hours
Why it's fatal: Dual massive accumulation of cGMP causes refractory vasodilatory collapse, fatal shock, and myocardial infarction.