Antiplatelet Drugs

Question 1

CCM 3rd Ed

Answer 1

Chapter 164 - Antiplatelet Drugs

Question 2

What is the primary indication for antiplatelet therapy?

Answer 2

Real of perceived hypercoagulable state or a state of increased platelet reactivity.

Question 3

What receptors are associated with which agonists?

Answer 3

GPCRs for ADP (P2Y1, P2Y12), thrombin (PAR1, PAR4), thromboxane (TP), serotonin (5-HT2A), and epinephrine (β2-adrenergic) among other agonists

Question 4

How is adp released from platelets and what receptors does it act on?

Answer 4

Released in alpha granules and acts on P2Y1 and P2Y12

Question 5

What do the P2Y receptors do?

Answer 5

P2Y1 - shape change and mild aggregation
P2Y12 - integrin activation, granule secretion and ADP-induced thromboxane A2 production

Question 6

clopidogrel MOA

Answer 6

P2Y12 inhibitor

Question 7

What COX pathway is mainly responsible for TXA2 mediated aggregation?

Answer 7

COX1

Question 8

Is asprin recommended as a sole agent?

Answer 8

No - due to the extreme antiplatelet variability in recept studies

Question 9

What do fibrinogen receptors inhibit?

Answer 9

The last common pathway - the expression of active fibrinogen receptor GPIIb/IIIa