Antianginal Drugs Flashcards
Nitroglycerin: Class
Nitrate
Nitroglycerin: Brand name
NitroStat
Nitroglycerin: Mechanism of Action
Reacts directly with nitrate receptor on SM cell to release NO -> GC -> cGMP -> relax smooth muscle cells -> vaso/venodilation
High first pass effect, so not good for oral
Nitroglycerin: Use
Taken sublingually (or transderm, IV) prn to relieve typical or variant angina
Nitroglycerin: Adverse Effects
Tolerance can develop quickly
Excessive hypotension, throbbing headache, dizziness, flushing
Avoid Viagra (-> hypotension)
Differentiate atenolol, metoprolol, and propranolol.
Atenolol: long acting B1 blocker
Metoprolol: short acting B1 blcoker
Propranolol: nonselective B blocker
Atenolol: mechanism of action
Selectively block B1 receptors -> Decrease HR, contractility, CO, BP (afterload), and wall tension -> reduce oxygen demand
Increase diastolic perfusion by increasing time for diastole
Beta blockers: contraindications, caution
Should NOT abruptly withdraw beta-blocker; can -> increased angina, acute MI
Should NOT be used for vasospastic angina
Verapamil: class, other drug in class
Class: calcium entry blocker
Other: Diltiazem
Verapamil: mechanism of action
Block calcium channels -> Decrease HR, contractility, CO, BP (afterload), and wall tension -> reduce oxygen demand
Increase diastolic perfusion by increasing time for diastole
Verapamil: Use
Acts directly on the heart and produces peripheral vasodilation to relieve both typical angina and variant angina
Aspirin: class, brand name
Antiplatelet agent
Bayer Aspirin
Aspirin: mechanism of action
Irreversibly blocks COX-1 in platelets, inhibiting formation of TBXA2 (vasoconstrictor, platelet aggregator)
Aspirin: use
Taken po for antiplatelet effects to prevent MI
Aspirin: adverse effects, contraindications
Ulceration of GI tract, bleeding disorders, tinnitus
Avoid in pts with nasal polyps and asthma
Clopidogrel: class, brand name
Antiplatelet agent
Plavix
Clopidogrel: mechanism of action
Blocks ADP receptors irreversibly to prevent aggregation mediated by ADP released by activated platelets
Clopidogrel: use
Taken po (in conjunction with aspirin) for primary or secondary prevention of TIA, stroke, angina, MI, post-angioplasty, ACS
Clopidogrel: adverse effects
Hemorrhage at any site, extensive skin bruising and discoloration
Abciximab: class, brand name
Platelet Gp IIb/IIa receptor blockers
ReoPro
Abciximab: mechanism of action
Monoclonal antibody – inhibits GP IIb/IIIa receptor to prevent binding of fibrinogen, vWF, others to activated platelets
Short acting
Abciximab: use
Used IV prior to PCI to prevent ischemic complications
Abciximab: adverse effects
Bleeding
Contraindicated with aneurysm, AV malformation, coagulopathy, intracranial mass, stroke, surgery, low platelets, trauma, vasculitis
(Brief) pathophysiology of angina
Myocardial oxygen demand outstrips oxygen supply
Why are beta blockers contraindicated in treatment of variant angina?
Spasm likely related to surge of NE
Beta blockers compete with NE at beta receptors, make more available to bind to alpha1 receptors -> INCREASE spasm
Given the pathophys of unstable angina or ACS, what drug action is essential to treat these conditions?
Suppression of platelet adhesion and aggregation!
