Antianginal Drugs Notes

Antianginal Drugs Notes

Definition and Purpose:

Antianginal drugs are medications used to prevent or treat angina pectoris

They work by improving the balance between myocardial oxygen supply and demand

Main Classes of Antianginal Drugs:

a) Nitrates

b) Beta-blockers

c) Calcium channel blockers

d) Potassium channel openers

e) Other agents (e.g., ranolazine)

Nitrates:

Mechanism: Vasodilation, reducing preload and afterload

Examples: Nitroglycerin, isosorbide mononitrate, isosorbide dinitrate

Uses: Acute angina relief and prophylaxis

Key points:

Rapid onset of action (especially sublingual nitroglycerin)

Risk of tolerance with continuous use

Common side effects: headache, hypotension

Beta-blockers:

Mechanism: Reduce heart rate and myocardial oxygen demand

Examples: Metoprolol, atenolol, propranolol

Uses: Angina prevention and treatment

Key points:

Effective for both stable and unstable angina

Contraindications: severe asthma, uncontrolled heart failure

Side effects: fatigue, cold extremities, sexual dysfunction

Calcium Channel Blockers:

Mechanism: Vasodilation and reduction of myocardial contractility

Examples: Amlodipine, diltiazem, verapamil

Uses: Angina prevention, especially in patients intolerant to beta-blockers

Key points:

Dihydropyridines (e.g., amlodipine) primarily cause vasodilation

Non-dihydropyridines (e.g., verapamil) also slow heart rate

Side effects: peripheral edema, constipation, headache

Potassium Channel Openers:

Example: Nicorandil

Mechanism: Vasodilation without affecting heart rate or contractility

Uses: Additional option for chronic stable angina

Key points:

Not widely available in all countries

Can cause headaches and dizziness

Other Agents:

Ranolazine:

Mechanism: Inhibits late sodium current in cardiac cells

Uses: Chronic stable angina

Advantages: Minimal effects on heart rate and blood pressure

Combination Therapy:

Often provides better symptom control than monotherapy

Common combinations:

Nitrate + Beta-blocker

Nitrate + Calcium channel blocker

Beta-blocker + Calcium channel blocker (with caution)

Clinical Considerations:

Individual patient factors (comorbidities, contraindications)

Monitoring for efficacy and side effects

Patient education on proper use and potential adverse effects

Regular follow-up and adjustment of therapy as needed

Non-pharmacological Approaches:

Lifestyle modifications (smoking cessation, exercise, diet)

Stress reduction techniques

Cardiac rehabilitation programs

Emergency Management:

Sublingual nitroglycerin for acute angina attacks

Patient education on when to seek emergency care

Remember: This is a general overview. Always consult current guidelines and prescribing information for detailed and up-to-date information on antianginal drug therapy.