Antiplatelet Drugs

Question 1

What are the 3 steps to thrombus (clot) formation?

Answer 1

1. Platelet adhesion
2. Platelet activation
3. Platelet aggregation

Question 2

What factors are responsible for platelet activation? What do these factors inc. expression of?

Answer 2

TXA2, ADP, collagen, 5HT and thrombin > Inc. expression of glycoprotein IIb/IIIa receptors

Question 3

How does aggregation of platelets occur?

Answer 3

cross-linking reaction due to fibrinogen binding to glycoprotein IIb/IIIa receptors

Question 4

Name some factors/drugs that can increase platelet activation.

Answer 4

ADP, 5HT, TXA2, thrombin, a2 agonists

Question 5

Name some factors/ drugs/ etc. that can decrease platelet activation.

Answer 5

PGI2, cAMP, ASA, clopidogrel, GP IIb/IIIa blockers

Question 6

What levels/dose of aspirin prevents MI recurrence?

Answer 6

low dose (baby aspirin) about 81 mg

Question 7

MOA clopidogrel?

Answer 7

block ADP receptors on platelets which decreases platelet activation

Question 8

Besides clopidogrel, what are other ADP receptor blockers?

Answer 8

prasugrel, ticagrelor

Question 9

Indications for use of clopidogrel and other ADP blocking agents?

Answer 9

alternatives to ASA in TIAs, post MI, and unstable angina

aspirin + ADP receptor blockers are used in patients with non-ST elevation ACS

Question 10

MOA Abciximab.

Answer 10

antagonist that binds to glycoprotein IIb/IIa receptors > dec aggregation by preventing the cross-linking reaction.

Question 11

Indication for glycoprotein IIb/IIIa antagonists?

Answer 11

acute coronary syndromes and postangioplasty

Question 12

Name glycoprotein IIb/IIIa receptors antagonists.

Answer 12

abciximab,
eptifibatide
tirofiban