Antianginal agents Flashcards
What 3 classes of medications are used to treat angina?
Nitrates
Calcium channel blockers
Beta-Blockers
Give 3 examples of nitrates
Nitroglycerine
Isosorbide mononitrate
Isosorbide dinitrate
Give 3 examples of calcium channel blockers
Amlodipine
Diltiazem
Verapamil
Give 2 examples of beta blockers
Metoprolol
Atenolol
Mechanism of action for nitrates?
Drugs converted to NO in endothelial cells
This increase cGMP causing vasodilation (venules>arterioles), which decreases preload and decreases myocardial O2 demand.
It also dilates coronary vessels which increases O2 supply
Routes of administration for nitrates?
Oral, transdermal, SL, IV
Adverse effects to nitrates?
Headache, hypotension, syncope, flushing, reflex tachycardia
DDIs with nitrates?
PDE-5 inhibitors (sildenafil) cause unsafe BP drop
1st line choice for an acute anginal episode?
SL nitroglycerine
MOA of CCBs in angina?
Block L-type Ca++ channels in smooth muscle leading to vasodilation (arterioles>venules), causing decreased afterload and decreased myocardial O2 demand.
Also dilates coronary arteries increasing O2 supply.
How are CCBs metabolized?
CYP450
What is the benefit to giving nitrates sublingual?
There is a high first pass effect, SL allows drug to enter through capillaries in mouth and avoid the liver.
Adverse effects of CCBs?
Negative chronotropic (Decrease HR, AV block) (V>D) Negative ionotropic (V>D) Hypotension, dizziness Peripheral edema (A>D>V) Constipation (Most commonly V)
DDIs with CCBs?
Grapefruit juice increases Cp
CYP450 inducers decrease Cp
When are CCBs a good choice for treatment of angina?
Variant angina
or
Stable angina if B-blockers are poorly tolerated
MOA of B-blockers in angina treatment?
Block cardiac B1 receptors causing decreased HR/BP/Contractility, which decreases myocardial O2 demand.
No effect of myocardial O2 supply because it is NOT A VASODILATOR
Which is primary renal metabolism, metoprolol or atenolol?
Atenolol
Adverse effects of beta blockers?
Decrease in contractility can cause acute HF
Can cause bronchospasms and worsen asthma
Increase blood lipids
Decrease peripheral circulation
Increase lipid solubility
Increase CNS ADRs causing sedation, sleep disturbances, fatigue
avoid in severe bradycardia, PVD, asthma,
DDIs with Beta blockers
Do not use with other negative ionotropic or chronotropic agents
1st line choice for chronic stable angina?
B blockers