Antianginal Drugs Flashcards
What is the most common cause of angina?
atherosclerotic CAD
What is variant (Prinzmetal’s) angina due to?
vasospasm of coronaries
What is the first line drug treatment for angina?
nitrates
Which drug is used to treat hypertensive emergencies?
nitroprusside
What are the main clinical indications of organic nitrates?
- angina pectoris
- hypertensive emergencies
- CHF
Does nitroglycerin or isosorbide mono/dinitrate act faster?
nitroglycerin (due to short HL)
What is the benefit of a nitroglycerin patch or ointment over the SL, buccal, or tablet formulations?
the patch and ointment are longer-lasting
Does isosorbide mono or dinitrate have a better bioavailability?
dinitrate (mononitrate not very bioavailable)
What are the main adverse effects associated with nitrates?
- exaggeration of therapeutic effects, including orthostatic hypotension, reflex tachycardia (baroreceptor reflex), and headache
- nitrate tolerance
How can nitrate tolerance be minimized?
- having a nitrate free interval
- using lowest effective dose
- using beta-blockers or Ca2+ channel blockers during nitrate free interval
Where are β1 vs. β2 receptors found?
- β1: cardiac muscle
- β2: cardiac muscle, bronchial smooth muscle, vascular smooth muscle (β2 promote relaxation)
Adverse effects associated with β-blockers?
bronchospasm, peripheral vasospasm, exaggerated therapeutic effects (ie, bradycardia), CNS effects (insomnia, depression, fatigue), sexual impotence
Contraindications for β-blockers?
- uncompensated CHF (don’t want to further decrease CO)
- marked bradycardia
- advanced AV block
- severe peripheral vasc. disease (due to potential for vasospasm)
- IDDM (potential for prolonged hypoglycemia)
- sexual impotence
- bronchospasm
MOA of ranolazine?
inhibition of late Na+ channel, which improves Ca2+ efflux
What are the 2 new classes of antianginal drugs?
- ranolazine
- ivabradine
MOA of ivabradine?
selective inhibition of funny current (If) at sinus node, thus reducing slow diastolic depolarization phase (=decreased heart rate)
What are the dihydropyridine vs. non-dihydropyridine Ca2+ channel blockers?
- Dihydropyridines: nifedipine, nicardipine, amlodipine
- Non-dihydropyridines: verapamil, diltiazem
Which of the calcium channel blockers have more inotropic and chronotropic effects?
verapamil and diltiazem more than nifedipine
Which of the calcium channel blockers have more vasodilatory effects?
nifedipine more than verapamil and diltiazem
Which calcium channel blocker is the best for increasing exercise time in patients with angina?
verapamil (bradycardic effect is good at reducing cardiac work during exercise)
Why might diltiazem be chosen over verapamil, despite decreasing contractility to a lesser degree?
diltiazem has limited side effects
Which is the only CCB that may be used in patients with systolic heart failure?
amlodipine
What is the pitfall of nicardipine?
it does not decrease cardiac contractility
Why does nifedipine cause peripheral edema?
because it vasodilates arterioles more than venules=leakage
Side effects of this drug include dizziness and constipation.
ranolazine
An excellent choice for angina pectoris patients with normal sinus rhythm who are unable to take a β-blocker.
ivabradine
What is the unique side effect associated with ivabradine?
Luminous Phenomena
How should you treat a heart failure patient who is NOT experiencing reduced EF?
lifestyle modifications
When would you add a β-blocker to SL nitroglycerin when managing a patient with stable angina?
when angina episodes become more frequent
If symptoms of angina cannot be controlled with nitroglycerin and β-blockers, how should you proceed?
consider a CCB, long-acting nitrate, ranolazine, ivabradine
What if a patient does not respond to medication management of angina?
consider CABG or PCI
