Agam Pharmacology Lecture Notes

Preface

• Agam is a group of medical students from Tamil Nadu and Pondicherry.
• Founded on November 18, 2017, to unite medicos for social and professional causes.
• The notes are a reference work by 2017 batch medical students.
• Intended as a revision note for university exams, not for first-time learning.

Acknowledgements

• Thanks to contributing doctors and students.
• Special thanks to leader Kareeshmaa H C.

Chapter 1: Renin-Angiotensin System

Captopril

• Introduction: Prototype of ACE inhibitors, affects angiotensin I but not II.
• Actions:
  • Increases plasma kinin levels.
  • Causes cough and angioedema due to elevated kinin.
  • Lowers BP based on Na+ status and RAS activity levels.
  • Safe in ischemic heart patients.
• Pharmacokinetics: 70% absorbed orally, food reduces bioavailability.
• Adverse Effects: Hypotension, hyperkalemia, cough, rashes, and angioedema.
• Interactions: Diuretics, NSAIDs, antacids affect efficacy and side effects.

Losartan

• Introduction: Angiotensin Receptor Blocker, selective for AT1.
• Actions:
  • Blocks all actions of Angiotensin II.
  • Fall in BP without affecting HR.
• Pharmacokinetics: Oral, not affected by food, 98% plasma-bound.
• Adverse Effects: Generally well tolerated, rare angioedema.
• Uses: Hypertension, CHF, MI, diabetic nephropathy.

Aliskiren

• Introduction: Direct Renin Inhibitor.
• Actions:
  • Reduces blood pressure by inhibiting renin.
  • Effective in Na+ depleted subjects.
• Pharmacokinetics: Oral administration, low bioavailability.
• Adverse Effects: Diarrhea, abdominal pain, contraindicated in pregnancy.

Chapter 2: Nitric Oxide and Vasoactive Peptide Signal Molecules

Nitric Oxide

• Generation and Fate: Produced from L-arginine by NOS.
• Actions:
  • Potent vasodilator.
  • Role in infection, inflammation, immune response.

Vasoconstricting Peptides

• Endothelins, Neuropeptide Y, Urotensin 2, Angiotensin.

Vasodilating Peptides

• Bradykinin, ANP, BNP, CNP, VIP, Substance P.

Endothelin Receptor Antagonists

• Bosentan, Ambrisentan, Macitentan, Sitaxsentan.

Chapter 3: Cardiac Glucosides and Drugs for Heart Failure

Congestive Cardiac Failure

• Digoxin:
  • Mechanism: Binds to Na+-K+ ATPase, increases intracellular Ca2+.
  • Actions: Increases contraction force, decreases heart rate.
  • Uses: Heart failure, atrial fibrillation.
  • Toxicity: Narrow therapeutic index, arrhythmias, GI and CNS effects.

Digitalis Toxicity

• Manifestations: Cardiac arrhythmias, GI and neurological symptoms.
• Treatment: Discontinue digoxin, correct K+ levels, use Digoxin antibodies.

Inodilators

• Drugs: Inamrinone, Milrinone, Levosimendan.
• Used for short-term management of severe CHF.

Sodium Nitroprusside

• Actions: Rapid vasodilator for hypertensive emergencies.
• Adverse Effects: Cyanide toxicity, CNS effects.

Chapter 4: Cholinergic Drugs

Antiarrhythmic Drugs

• Lidocaine: Blocks Na+ channels, treats ventricular arrhythmias.
• Amiodarone: Class III, used for resistant arrhythmias.
• Verapamil: Class IV, for PSVT, not for ventricular arrhythmias.
• Adenosine: Effective for PSVT, safe in hypotension.

Chapter 5: Antianginal and Other Anti-ischemic Drugs

Antianginal Drugs

• Nitrates: Vasodilators that reduce heart workload.
• Nifedipine: Calcium channel blocker for hypertension.
• Nicorandil: Dual mechanism, activates K+ channels.

Myocardial Infarction Therapy

• Treatment: Pain relief, oxygenation, arrhythmia prevention.

Chapter 6: Antihypertensive Drugs

Antihypertensives

• ARBs: Losartan, Candesartan, Valsartan, for hypertension and CHF.
• Hypertensive Emergencies: Managed with parenteral drugs like Nicardipine and Nitroprusside.

Hydralazine

• Uses: Heart failure, pre-eclampsia.

Minoxidil

• Used topically for alopecia treatment.

Summary

• Comprehensive coverage of pharmacology topics relevant for medical students.
• Notes include drug mechanisms, uses, and adverse effects.