Antiplatelet Drugs

Question 1

Aspirin MOA

Answer 1

Inhibits cyclo-oxygenase
This prevents thromboxane A2 production
This reduces platelet activation & aggregation

Question 2

Aspirin side effects

Answer 2

Bleeding
Blockage of prostaglandin production (GI ulceration, bronchospasm etc)

Question 3

Clopidogrel & prasugrel drug class & MOA

Answer 3

P2Y12 inhibitors - ADP receptor antagonist (prevents platelet activation & aggregation)

Question 4

Clopidogrel & prasugrel side effects

Answer 4

Bleeding

Question 5

Dipyridamole drug class & MOA

Answer 5

PDE inhibitor - increases cAMP production which inhibits platelet aggregation

Question 6

Dipyridamole side effects

Answer 6

Bleeding

Question 7

Abciximab drug class & MOA

Answer 7

GP IIb/IIIa inhibitor - inhibits platelet aggregation (platelets attach to each other via GP IIb/IIIa & fibrinogen)

Question 8

Name three molecules/granules that are important in platelet activation & aggregation

Answer 8

Thrombin, thromboxane A2, ADP
(note: these granules are released by platelets and also have receptors on platelet membranes)

Question 9

Name 2 molecules/granules that are released by platelets that allow them to attach to each other

Answer 9

GPIIbIIIa & fibrinogen

Question 10

How would you treat bleeding caused by an anti-platelet drug? What changes would you make to a patients drug regime who is on anti-platelets and about to undergo surgery?

Answer 10

• If serious bleeding - can reverse with platelet transfusion
• Stop anti-platelet agents 7 days prior to elective operations
• Anti-platelet drugs tend to affect platelet function for their 7-10 day lifespan

Question 11

State the formulation of the four key anti-platelet drugs

Answer 11

Cyclooxygenase i (Aspirin) (O)
P2RY12 (Clopidogrel) (O)
PDE i (Dipyridamole) (O)
GP IIb/IIIa i (abciximab) (IV)