Antianginal Drugs Flashcards
What is angina?
crushing, strangling chest pain caused by accumulation of metabolic waste products in muscle. Reduced blood flow and oxygen delivery
What drugs increase coronary blood flow?
nitrates and calcium channel blockers
What drugs decrease HR?
Beta blockers and some calcium channel blockers
Which drugs decrease preload?
nitrates
Which drugs reduce afterload?
calcium channel blockers
Which type of angina is not exercise induced?
Variant Angina
What types of angina occur at rest?
Variant and unstable angina
Which types of angina have a ST segment depression?
Stable and some unstable
Which types of angina have a raised ST segment
variant angina
What causes stable vs. unstable vs. variant angina?
Stable is caused by atherosclerotic lesion
Unstable is a mixture of a lesion and vasospasm
Variant is spasm of coronary artery
What do the nitrates do and what is their mechanism of action?
act on endothelial cells to release NO, causing vasodilation and reducing venous return to the heart, decreasing preload, and vasodilation of arteries, reducing afterload
What are the nitrate drugs?
Nitroglycerin, isosorbide dinitrate and mononitrate, amyl nitrite
What is a side effect of amyl nitrite
Amyl nitrite can cause methemoglobinemia, used for patients with cyanide poisoning
What conditions are nitrates used for?
Any form of angina - stable, unstable, variant
What are side effects of nitrates?
orthostatic hypotension, reflex tachycardia, throbbing headache, methemoglobinemia. Sublingual drugs can cause burning sensation; oral results in few SE.
What is nitrate tolerance?
Tolerance occurs due to depletion of intracellular sulfhydryls and densensitization of soluble guanylyl cyclase.
It’s recommended to avoid nitrates at night when oxygen needs are the lowest.
Which Beta blockers are used for Angina?
Atenolol and Metapropolol - selective B1 blockers
Nadolol and Propanolol - non-selective beta blockers
How do Beta Blockers treat Angina?
Prophylactic Tx of stable angina, can be combined with nitrates to reduce HR
Reduce HR, CO, and conduction velocity
Decrease renin release
Decrease sympathetic outflow to periphery
What are side effects of Beta Blockers
can precipitate heart failure, hypotension, increased airway resistance (non-selective), depression, insomnia, NVD, ED.
Contraindications for Beta Blockers
Patients with asthma
diabetics, B blockers masks hypoglycemic shock
Patients with CHF
If patients don’t respond to Beta blockers, may have variant angina
What are the Calcium channel blockers that cause bradycardia?
Verapamil, Diltiazem, Bepridil
Which calcium channel blockers cause tachycardia
Dihydropyridines
What types of angina can calcium channel blockers be used for?
All 3: stable, unstable, variant. Reduces vasospasm, afterload and preload
What are side effects of Verapamil, Diltiazem, and Bepridil
Bradycardia, Hypotension, CHF, Skin rash, Constipation. Can be combined with nitrates
What are the side effects of Dihydropyridines (the DIPINES)
Tachycardia, hypotension, dizziness, skin rash, peripheral edema. CANNOT be combined with nitrates due to tachycardia x2
How does aspirin treat angina?
antiplatlet function, prevents blood clotting with turbulent flow. Lose dose should be used on a daily basis
How does dipyridamole treat angina?
Blocks adenosine reuptake in coronary arteries, acting as a vasodilator. Used in Unstable angina only!
What does Ranolazine do?
Inhibits FA oxidation since it uses a lot of O2. Use carbohydrates for energy instead which require less oxygen. Overall, reduce O2 consumption in heart.
How does Ivabradine treat angina?
Blocks sodium channel in SA node, use for both arrhythmias and angina
What is combination therapy treatment for angina?
Aggrenox: aspirin/extended release dipyridamile
