I want to study cvs of pharmacology by kdt
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I have enough context now. KDT is not in the library, but I have confirmed excellent CVS pharmacology coverage in the available books. Let me compile a complete, structured study guide for CVS pharmacology in the style of KDT — covering all the major topic areas.
CVS Pharmacology - Complete Study Guide
Note: KD Tripathi's Essentials of Medical Pharmacology is not in this library's collection. The guide below is drawn from Katzung's Basic and Clinical Pharmacology (16th ed.), Lippincott Illustrated Reviews: Pharmacology, and Goodman & Gilman's - all of which cover the same CVS pharmacology syllabus as KDT, often in greater depth.
CVS Pharmacology - Topic Map (KDT Syllabus Aligned)
1. CARDIAC GLYCOSIDES (Digitalis)
Prototype: Digoxin
| Feature | Details |
|---|---|
| Mechanism | Inhibits Na⁺/K⁺-ATPase → ↑ intracellular Na⁺ → ↑ Ca²⁺ via Na⁺/Ca²⁺ exchanger → ↑ contractility |
| Positive inotrope | ↑ force of contraction (direct) |
| Negative chronotrope | ↓ HR (vagal stimulation) |
| Negative dromotrope | ↓ AV conduction (↑ PR interval) |
| Uses | Heart failure (HFrEF), atrial fibrillation/flutter |
| Toxicity | Arrhythmias, GI symptoms (N/V), yellow-green vision (xanthopsia), gynaecomastia |
| Toxic predisposing factors | Hypokalaemia, hypomagnesaemia, hypercalcaemia, hypothyroidism, renal failure |
| Antidote | Digoxin-specific Fab antibody fragments (Digibind) |
2. ANTIARRHYTHMIC DRUGS (Vaughan-Williams Classification)
Class I - Na⁺ Channel Blockers
| Class | Drug | Key Feature |
|---|---|---|
| IA | Quinidine, Procainamide, Disopyramide | ↓ Phase 0 upstroke; prolongs AP duration; anticholinergic effects |
| IB | Lidocaine, Mexiletine, Phenytoin | Shorten AP duration; used in ventricular arrhythmias |
| IC | Flecainide, Propafenone | Marked ↓ Phase 0; used in SVT; contraindicated post-MI (CAST trial) |
Class II - Beta-Blockers
- Drugs: Metoprolol, Esmolol, Propranolol
- Mechanism: Block β₁ receptors → ↓ SA node automaticity, ↓ AV conduction
- Uses: SVT, post-MI, AF rate control, hypertension
Class III - K⁺ Channel Blockers
- Drugs: Amiodarone, Sotalol, Dofetilide, Ibutilide, Dronedarone
- Mechanism: Prolong repolarization → ↑ refractory period → ↑ QT interval
- Amiodarone - broadest spectrum antiarrhythmic; acts on all 4 Vaughan-Williams classes; half-life 40-55 days; major toxicities: pulmonary fibrosis, thyroid dysfunction (hypo/hyperthyroid), corneal microdeposits, hepatotoxicity, photosensitivity, peripheral neuropathy
Class IV - Ca²⁺ Channel Blockers (Non-DHP)
- Drugs: Verapamil, Diltiazem
- Block L-type Ca²⁺ channels in SA/AV nodes
- Uses: SVT, AF/flutter rate control, angina
Miscellaneous Antiarrhythmics
- Adenosine: Drug of choice for paroxysmal SVT; half-life ~10 seconds; mechanism: activates K⁺ channels → hyperpolarization of AV node
- Magnesium sulfate: Torsades de pointes, digoxin-induced arrhythmias
- Atropine: Sinus bradycardia
- Isoprenaline: Complete heart block (temporary)
3. ANTIHYPERTENSIVE DRUGS
Step-wise Classification
1. Diuretics
- Thiazides (Hydrochlorothiazide, Chlorthalidone) - first-line; mechanism: inhibit NaCl cotransporter in DCT
- Loop diuretics (Furosemide) - used in hypertension with CKD/heart failure
- K⁺-sparing (Spironolactone, Eplerenone) - especially in primary hyperaldosteronism and HFrEF
2. Beta-Blockers
- Propranolol (non-selective), Metoprolol/Atenolol (β₁-selective), Carvedilol/Labetalol (α+β blockade)
- Mechanism in HTN: ↓ cardiac output + ↓ renin release
- Carvedilol/Nebivolol - also useful in heart failure
3. Calcium Channel Blockers (CCBs)
- Dihydropyridines (Amlodipine, Nifedipine, Felodipine) - preferential vascular effect
- Non-dihydropyridines (Verapamil, Diltiazem) - cardiac + vascular
4. ACE Inhibitors (ACEIs)
- Drugs: Enalapril, Lisinopril, Ramipril, Captopril
- Mechanism: Block ACE → ↓ Angiotensin II → vasodilation + ↓ aldosterone
- Key adverse effects: Dry cough (bradykinin accumulation), angioedema (contraindicated in pregnancy)
- Benefits beyond BP: Nephroprotective in diabetic nephropathy, post-MI, heart failure
5. Angiotensin II Receptor Blockers (ARBs)
- Drugs: Losartan, Valsartan, Telmisartan, Candesartan
- Block AT₁ receptor; no cough (no bradykinin effect)
- Used when ACEIs cause cough
6. Direct Renin Inhibitor
- Aliskiren - blocks renin; rarely used alone
7. Alpha Blockers
- α₁-selective: Prazosin, Terazosin, Doxazosin - also useful in BPH
- Non-selective: Phentolamine (used in phaeochromocytoma crisis)
8. Central Sympatholytics
- Methyldopa - drug of choice in hypertension in pregnancy
- Clonidine - α₂ agonist; rebound hypertension on abrupt withdrawal
9. Direct Vasodilators
- Hydralazine - arteriolar dilator; used in HTN in pregnancy (with methyldopa); reflex tachycardia; lupus-like syndrome
- Minoxidil - most powerful oral vasodilator; hirsutism; used in severe/resistant HTN
- Sodium nitroprusside - IV, hypertensive emergency; releases NO; cyanide toxicity with prolonged use
- Diazoxide - IV; releases K⁺ from pancreatic β-cells → hyperglycaemia
JNC/hypertensive emergency drugs: Labetalol (IV), Nicardipine (IV), Clevidipine (IV), Fenoldopam
4. DRUGS USED IN HEART FAILURE
| Drug Class | Examples | Mechanism |
|---|---|---|
| ACEIs/ARBs | Enalapril, Sacubitril+Valsartan (Entresto) | ↓ preload + afterload; ↓ remodelling |
| Beta-blockers | Carvedilol, Metoprolol succinate, Bisoprolol | ↓ sympathetic activation; reduce mortality |
| Aldosterone antagonists | Spironolactone, Eplerenone | ↓ aldosterone-mediated fibrosis |
| Loop diuretics | Furosemide, Torsemide | Symptom relief (↓ volume overload) |
| SGLT2 inhibitors | Dapagliflozin, Empagliflozin | Reduce HF hospitalizations (HFrEF + HFpEF) |
| Ivabradine | Ivabradine | Blocks I_f in SA node; ↓ HR without affecting contractility |
| Digoxin | Digoxin | ↑ contractility; symptom relief but no mortality benefit |
| Hydralazine + Isosorbide dinitrate | H-ISDN | Alternative when ACEIs/ARBs not tolerated; especially in Black patients |
5. ANTIANGINAL DRUGS
Types of Angina: Stable (effort), Unstable (rest), Variant (Prinzmetal's - vasospasm)
Organic Nitrates
- Drugs: GTN (nitroglycerin), Isosorbide dinitrate, Isosorbide mononitrate
- Mechanism: Metabolized to NO → ↑ cGMP → vascular smooth muscle relaxation → primarily venodilation (↓ preload)
- Tolerance: Develops with continuous use; prevented by nitrate-free interval (8-12 hours)
- Adverse effects: Headache (most common), orthostatic hypotension, reflex tachycardia
- Contraindicated with PDE5 inhibitors (Sildenafil) - severe hypotension
Beta-Blockers
- ↓ HR and contractility → ↓ O₂ demand
- Drug of choice in stable/effort angina
- Contraindicated in variant (Prinzmetal's) angina - may worsen vasospasm
Calcium Channel Blockers
- All types of angina including variant angina
- Amlodipine/Nifedipine (DHP) - vasospasm; Verapamil/Diltiazem - rate control + angina
Newer Antianginals
- Ranolazine: Inhibits late INa; used as add-on therapy; no effect on HR/BP
- Ivabradine: If channel blocker in SA node; ↓ HR only
- Nicorandil: K⁺-ATP channel opener + nitrate-like action; used in refractory angina
6. ANTITHROMBOTIC DRUGS
Antiplatelet Drugs
| Drug | Mechanism | Notes |
|---|---|---|
| Aspirin | Irreversibly inhibits COX-1 → ↓ TXA₂ | Low dose (75-100 mg) for antiplatelet effect |
| Clopidogrel, Ticagrelor, Prasugrel | P2Y₁₂ ADP receptor blockers | Used in ACS, post-stent; combined with aspirin (DAPT) |
| Dipyridamole | Inhibits PDE + adenosine uptake → ↑ cAMP | Used with aspirin in stroke prevention |
| Abciximab, Eptifibatide, Tirofiban | GPIIb/IIIa receptor blockers | IV use in PCI |
Anticoagulants
| Drug | Mechanism | Notes |
|---|---|---|
| Heparin (UFH) | Activates antithrombin → inhibits Xa and IIa | IV/SC; monitor aPTT; antidote: Protamine sulphate |
| LMWH (Enoxaparin) | Mainly anti-Xa | SC; no routine monitoring; preferred in pregnancy |
| Warfarin | Inhibits Vit K epoxide reductase → ↓ II, VII, IX, X | Oral; monitor INR; antidote: Vit K / FFP |
| Dabigatran | Direct thrombin inhibitor | Oral NOAC; antidote: Idarucizumab |
| Rivaroxaban, Apixaban | Direct Xa inhibitors | Oral NOACs; antidote: Andexanet alfa |
| Fondaparinux | Selective anti-Xa (via antithrombin) | SC |
Thrombolytics (Fibrinolytics)
- Streptokinase, Alteplase (tPA), Reteplase, Tenecteplase
- Mechanism: Activate plasminogen → plasmin → clot lysis
- Uses: STEMI, massive PE, ischaemic stroke (within 4.5 hours)
7. DRUGS USED IN DYSLIPIDAEMIAS (Hypolipidaemic Drugs)
| Drug | Mechanism | Effect |
|---|---|---|
| Statins (Atorvastatin, Rosuvastatin) | HMG-CoA reductase inhibitors | ↓↓ LDL (primary); ↑ HDL; ↓ TG |
| Fibrates (Fenofibrate, Gemfibrozil) | PPARα agonists | ↓↓ TG; ↑ HDL |
| Niacin (Nicotinic acid) | ↓ VLDL synthesis; ↓ lipolysis in adipose | ↑↑ HDL; ↓ TG, LDL; flushing (ASA pretreatment) |
| Bile acid resins (Cholestyramine) | Bind bile acids in gut | ↓ LDL; ↑ TG |
| Ezetimibe | Blocks NPC1L1 in gut | ↓ LDL absorption; add-on to statins |
| PCSK9 inhibitors (Evolocumab, Alirocumab) | Monoclonal antibodies blocking PCSK9 | ↓↓↓ LDL |
| Statin adverse effects | Myopathy/rhabdomyolysis, ↑ LFTs, ↑ blood glucose | Contraindicated in pregnancy |
8. DIURETICS (CVS applications)
| Class | Drugs | Site of Action | Uses |
|---|---|---|---|
| Loop | Furosemide, Ethacrynic acid | TAL of Loop of Henle | Acute HF, pulmonary oedema, hypertensive emergency |
| Thiazide | HCTZ, Chlorthalidone, Indapamide | DCT | Hypertension (first-line), mild heart failure |
| K⁺-sparing | Spironolactone, Eplerenone, Amiloride | Collecting duct | HFrEF, hyperaldosteronism, used with loop/thiazide to prevent hypokalaemia |
| Carbonic anhydrase inhibitors | Acetazolamide | PCT | Altitude sickness, glaucoma |
| Osmotic | Mannitol | Proximal tubule + descending loop | Cerebral oedema |
High-Yield KDT-Style Points to Remember
- Quinidine - cinchonism (tinnitus, blurred vision), torsades de pointes, ↑ digoxin levels
- Procainamide - lupus-like syndrome (anti-histone antibodies)
- Lidocaine - no oral bioavailability; CNS toxicity (convulsions) at high doses
- Adenosine - blocked by theophylline (adenosine receptor antagonist); potentiated by dipyridamole
- Verapamil + Beta-blocker = dangerous combination (complete AV block)
- Nitrate tolerance prevented by: eccentric dosing, nitrate-free period, N-acetylcysteine
- Methyl-DOPA - Coombs positive haemolytic anaemia; safe in pregnancy
- Clonidine withdrawal - rebound hypertension (treat with IV phentolamine or restart clonidine)
- Minoxidil - causes hirsutism (used topically for alopecia); requires beta-blocker + loop diuretic co-administration
- Sacubitril/Valsartan (Entresto) - ARNI; contraindicated with ACEIs (risk of angioedema); 36-hour washout needed
- Ticagrelor vs Clopidogrel - ticagrelor is reversible; does NOT require hepatic activation (unlike clopidogrel - prodrug)
- Warfarin interactions: Potentiated by: metronidazole, fluconazole, amiodarone, NSAIDs; Inhibited by: rifampicin, carbamazepine, phenytoin
Sources:
- Katzung's Basic and Clinical Pharmacology, 16th Ed., Chapters 11-14
- Lippincott Illustrated Reviews: Pharmacology, Chapter 11 (Antiarrhythmics), Chapters 16-17 (Antihypertensives, Heart Failure)
Important note: KD Tripathi's Essentials of Medical Pharmacology is not in the available textbook library. All content above covers the identical CVS pharmacology syllabus and is consistent with KDT's organization. For the exact KDT text, you would need to access the book directly.
Would you like me to go deeper on any specific topic - for example, a detailed breakdown of antiarrhythmics, antihypertensives, heart failure drugs, or anticoagulants?
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