Heart Antianginal Agents (Chapter 46)

Flashcards covering nitrates, beta-blockers, calcium channel blockers, and ranolazine (piperazine acetamide) antianginal agents, including mechanism, forms, contraindications, interactions, administration, and clinical considerations.

What are the two primary ways antianginal agents improve blood delivery to the heart muscle?

Dilating blood vessels and decreasing the work of the heart to reduce oxygen requirements.

Which drug classes are included under antianginal agents in this chapter?

Nitrates, beta-adrenergic blockers, calcium channel blockers, and piperazine acetamides.

Name the nitrates listed in the notes.

Isosorbide dinitrate, isosorbide mononitrate, and nitroglycerin.

What is the main pharmacologic effect of nitrates on hemodynamics?

Drop in blood pressure with decreased preload and afterload, reducing cardiac workload and oxygen demand.

Do nitrates repair damaged coronary vessels?

No; they improve blood flow by relaxing surrounding vessels where relaxation can occur.

List common Nitroglycerin administration forms.

Sublingual/buccal tablet, translingual spray, IV bolus, IV infusion, transdermal patch, topical ointment/paste, transmucosal agent, and slow-release forms.

Onset and duration for isosorbide dinitrate/mononitrate (oral forms)?

Onset 14–45 minutes (up to 4 hours with sustained release); duration 4–6 hours (6–8 hours with sustained release).

What are contraindications/cautions for nitrates?

Anemia, hypotension, hypovolemia; head trauma/cerebral hemorrhage.

What interactions affect nitrate effectiveness or safety?

Ergot derivatives decrease nitrate effect; nitrates decrease heparin effects; nitrates with PDE-5 inhibitors can cause hypotension and cardiovascular events.

List common adverse effects of nitrates.

Effects related to vasodilation: headache, dizziness, weakness; GI effects; hypotension with reflex tachycardia and angina; skin effects like flushing/pallor; contact dermatitis with transdermal; tolerance with continual use.

What is the recommended sublingual nitrate administration protocol during an acute angina attack?

Have the patient sit or lie down, moisten the mouth, place tablet under the tongue, ensure it fizzles, and repeat every 5 minutes for up to 3 doses; IV forms are preferred for unstable angina or acute MI.

Beta-adrenergic blockers drugs listed.

Atenolol, metoprolol, propranolol, nadolol.

How do beta-blockers help with angina management?

Decrease cardiac output and myocardial oxygen consumption and lower blood pressure; used for long-term management; not used for prinzmetal angina.

Beta-blocker adverse effects relate to what physiological mechanism?

Sympathetic block; lower doses are used for angina than for hypertension, so fewer side effects are seen.

Calcium channel blockers listed.

Amlodipine, diltiazem, nicardipine, nifedipine, verapamil.

Non-dihydropyridine vs dihydropyridine CCBs?

Dihydropyridines end in 'ine' (e.g., amlodipine, nifedipine, nicardipine); non-dihydropyridines include diltiazem and verapamil.

HF patients should avoid which CCBs and why?

Non-dihydropyridine CCBs, because they can further decrease heart muscle function.

Effect of CCBs on preload and afterload?

Decrease both preload and afterload, reducing myocardial workload and oxygen consumption.

Uses of CCBs in angina?

Used for prinzmetal (variant) angina and chronic angina.

Piperazine acetamide agent name?

Ranolazine (Ranexa) – ER tablet form; also a Class Id antiarrhythmic.

Additional antianginal benefits of ranolazine?

Decreases blood glucose levels in diabetics; reduces incidence of V-fib, A-fib, and bradycardia in chronic angina; decreases workload of the heart; mechanism not well understood.

Ranolazine cautions/contraindications?

Prolongs QT interval; avoid in patients with prolonged QT or with other QT-prolonging drugs; caution with CYP3A inhibitors.