Pharm - ACS Flashcards
What is the goal of therapy for a patient with UA or NSTEMI?
- prevent progression to STEMI and death
- prevent ischemia and life-threatening ventricular arrhythmias
- relief of ischemic pain
- prevent further thrombosis of or embolism from an ulcerated plaque
For a patient presenting with UA (or any ACS), what is the correct aspirin product to use? and the dose?
- chewable, uncoated aspirin
- 162-325 mg ASAP
- continued indefinitely
MoA of aspirin in treating UA/NSTEMI
- in cytosol AA (arachadonic acid) is converted to 2 prostaglandin intermediates by COX-1 and COX-2
- COX-1 is essential for synthesis of thromboxane A2 (TxA2)
- TxA2 stimulates platelet aggregation and vasoconstriction
- aspirin blocks COX-1, reducing production of TxA2 = decreased platelet aggregation
(flow chart on pg 6 if needed)
appropriate dosing of sublingual nitroglycerin for UA
- 3 sublingual nitroglycerin tabs 0.4 mg
- one at a time, spaced 5 min apart
MoA of nitroglycerin
- nitrates enter vascular smooth muscle and form NO
- NO stimulate an enzyme to form cGMP which does 2 things:
- inhibits Ca++ entry into cell (relaxation)
- causes downstream dephosphorylation of myosin = relaxation = vasodilation
(flow chart on pg. 7 if needed)
ADRs of sublingual nitro
- HA (intense) and flushing
- SL tingling
- postural hypotension
- occasional nausea
- tachycardia
ADRs of aspirin
(Letassy didn’t have specific list in packet)
- chewing aspirin can irritate mouth, make sure to rinse
- takes 7 days to reverse so stop 1 week before procedure to prevent bleeding
define the term cardioselectivity in context of a cardioselective beta blocker
- refers to the ability of a drug to preferentially block the B-1 receptor
- cardioselective beta blockers have the potential advantage of less likely to cause bronchoconstriction or peripheral vasodilation
- the selectivity is usually lost at higher doses
- best one is metroprolol tartrate**
define dual antiplatelet therapy (DAPT)
- all patients w/ NSTEMI should be treated w/ aspirin and a P2Y12 receptor blocker (ASA + P2Y12RB)
- it’s directed at limiting platelet adhesion and aggregation (early steps of coronary a. thrombus formation)
- it has been shown to significantly reduce the risk of cardiovascular death, nonfatal MI or stroke
what is the recommended duration of DAPT for patients w/ stent placement secondary to UA/NSTEMI
- at least 12 months
- unless high bleed risk
What are the P2Y12 receptor blockers? (the 4 that letassy gave us)
- clopidogrel (Plavix)
- prasugrel (effient)
- ticagrelor (brilinta)
- cangrelor (Kengreal)
MoA of clopidogrel (Plavix)
- P2Y12 ADP receptor inhibitor
- requires 2 steps for biotransformation to active metabolite
- irreversibly blocks the P2Y12 portion on the ADP receptor on platelet surface
- reduced platelet aggregation
MoA of ticagrelor
- noncompetitive, reversible, P2Y12 receptor antagonist
- reversibly binds to ADP receptors on platelet surface
- prevents ADP-mediated platelet activation and aggregation
In treating a patient with UA, what is the appropriate dose of clopidogrel?
- **Loading dose: 300-600 mg
- followed by 75 mg orally daily
In treating a patient with UA, what is the appropriate dose of prasugrel?
- **loading dose: 60 mg
- followed by 10mg orally daily
- 5mg daily if used in pts w/ high bleeding risk