Anti-Anginal Flashcards
Aspirin (Bayer, Ascriptin, Halfprin)
Drug class: salicylate, analgesic, anti-inflammatory, anti-platelet, anti-pyretic, prevention of MI
PD: at low doses (<325mg/day), tends to irreversibly inhibit COX1 in platelets, leading to decreased formation of TBX A2 (vasoconstrictor, platelet aggregator) and transiently inhibit COX2 in endothelium, leading to transient decreased formation of PGI2 (vasodilator, inhibitor of platelet aggregation)
PK: F ~60%, Tmax variable (e.g. alkaseltzer), metabolized to salicylate, t1/2 3-4h, duration of action 4-24h, 90% excreted as salicylate metabolites in urine
Toxicity: esp at high doses can cause ulceration of GI tract, bleeding disorders, tinnitus
Interactions: inhibit tubular secretion of methotrexate, potentiate bleeding from warfarin
Special consideration: avoid in pts with nasal polyps and asthma, regular, buffered, enteric coated
Indication and dose: for anti-platelet effects, 81mg-325mg qd, for arthritis 2.4-3.6g qd in divided doses.
Nitroglycerin (TNG, NitroStat, Isosorbide Nitrate)
Drug class: organic nitrate, antianginal, vasodilator, venodilator
PD: reacts directly with nitrate receptor on SM cell, sulfhydryl groups in receptor reduce organic nitrate to NO2 and then NO, which crosses into SM cells, activates guanylate cyclase, leading to production of cGMP from GTP, cGMP acts to relax SM cells
PK: well absorbed po, but very high first pass effect, prompt onset (1-2min), when taken as SL tablet or spray, also given transdermally or iv
Toxicity: xs hypotension, esp if pt is volume depleted, throbbing headache, flushing
Interactions: xs. Hypotensions with other vasodilators, severe hypotension with Viagra (sildenafil)
Special consideration: remove transdermal patch before defibrillation, use only fresh TNG tablets, tolerance can develop quickly (give 8h holiday each night)
Indication and dose/route: for angina
Clopidogrel (Plavix), Prasugrel, Ticagrelor
Drug class: inhibitor of ADP-induced platelet aggregation
PD: blocks ADP receptors irreversibly, which then helps prevent aggregation mediated by ADP released by an activated platelet from recruiting other platelets via GP IIb/IIIa, useful in 1’ and 2’ prevention of TIA, stroke, angina, MI, angioplasty, stent placement, ACS, etc, parent drug is not active, but one metabolite is pharmacologically active
PK: well absorbed, onset 1-2h after oral dose, hepatic metabolism, t1/2 ~8h
Toxicity: hemorrhage at virtually any site, extensive skin bruising and discoloration
Interactions: may inhibit CYP3A, increased risk of bleeding when given with aspirin (but also increased efficacy)
Special consideration: careful risk/benefit assessment in each pt, AND it’s quite expensive
Indication: for ACS, LD 300mg up front, then 75mg qd (in conjunction with ASA 81-325mg daily)
Abciximab (ReoPro, Tirofiban, Aggrastat, Eptifibate, Integrilin)
Drug class: Fab fragment chimeric monoclonal ab, adjunct to PCI to prevent ischemic complications, treatment of MI
PD: non-competitive inhibitor of the GP IIb/IIIa receptor, prevents binding of fibrinogen, vWF, and other adhesive ligands to the receptor on activated platelets. Need to block >80% of these receptors to maximally inhibit platelet
PK: IV bolus followed by iv infusion, t1/2 about 30min, bleeding time declines to <12min within 12h of stopping infusion
Toxicity: contraindicated in presence of aneurysm, AV malformation, bleeding, coagulopathy, GI bleed, intercranial mass, retinal bleeding, stroke, surgery, low platelets, trauma, vasculitis
Interactions: additive effects with aspirin, clopidogrel, heparin, low dose t-Pa
Special consideration: exact role is still being defined, and evolves over time, cost is a big factor
Indication and dose: when PCI is planned to treat ACS, .25mg/kg bolus (e.g. 20mg) followed by 10mcg/min for 18-24h
