antiplatelets

Question 1

aspirin

Answer 1

MOA: irreversible inhibition of platelet COX 1 and 2
Pharm: rapidly absorbed by upper GIT, enteric coating slows it down, 4 hour to peak
adverse effects: the most significant adverse reactions associated with aspirin- gi bleeding and irritation

Therapy: MI prophylaxis, alone or in combination w/ thrombolytic in acute MI, acute phase of ischemic stroke, stroke prophylaxis, unstable angina, preeclapsia

Question 2

dipyridamole

Answer 2

MOA: phosphodiesterase inhibition and or blockade of uptake of adenosine, increases cAMP, inhibits platelt aggregation, oral admin

Adverse: headache, GI upset, dizziness
Therapy: secondary prevention of stroke when its combined with low dose aspirin

Question 3

clopidogrel, prasugrel, ticagrelor

Answer 3

MOA: inhibit ADP binding to the P2Y receptor, clopidogrel and prasugrel are irreversible antagonists that inhibit platelet aggregation for the life of the platelet. Ticagrelor are advantageous

Pharmacokinetics: clopidogre- prodrug (via CYP2C19). Prasugrel prodrug that undergoes hydrolysis and CYP 450- 3A4m 2B6). Ticagrelor not a prodrug. PRasugrel has higher potency than clopidogrel

adverse: bleeding, ticgrelor-dyspnea.

cyp2c19 is inhibited by proton pump inhibitors

Question 4

therapeutic uses of clopidogrel, prasugrel and ticarelor

Answer 4

clopidogrel: better than aspirin for secondary prevention of stroke, unstable angina, reducing the rate of stroke, MI, and death in pt with recent Hx of MI or stroke
prasugrel: indicated to reduce the rate of thrombotic CV events, percutaneous coronary intervention

Ticagrelor: reduction of risk of CV death, MI and stroke

Question 5

Abciximab and EPtifibatide

Answer 5

glycoprotein 2b/3a receptor blocker

MOA: abcximab consists of the Fab fragment of a chimeric prevents binding of fibrinogen binding and cross linking of platlets. abcixib

Eptifibatide: also prevents platelt aggregation by preventing fibrinogen cross linking of platelts, competitive reversible inhibitorof fribrinogen bindig

Pharm: iv admin 10->30 minute half life

Adverse effects: bleeding, thrombocytopenia renal contra

preventing platelt aggregation and thrombosis in pts undergoing percutaneuous coronary interventions

eptifibatide is wused with unstable angina and MI