How long does it take for plavix to begin working?

Plavix (clopidogrel) must be metabolized by CYP450 enzymes to produce the active metabolite that inhibits platelet aggregation. The active metabolite of clopidogrel selectively inhibits the binding of adenosine diphosphate (ADP) to its platelet P2Y12 receptor and the subsequent ADP-mediated activation of the glycoprotein (GPIIb/IIIa complex) and that inhibits platelet aggregation. This action is irreversible.

Platelets exposed to clopidogrel's active metabolite are affected for the remainder of their lifespan (about 7 to 10 days).

Platelet aggregation induced by agonists other than ADP is also inhibited by blocking the amplification of platelet activation by released ADP.

Dose-dependent inhibition of platelet aggregation can be seen 2 hours after single oral doses of Plavix. Repeated doses of 75 mg Plavix per day inhibit ADP-induced platelet aggregation on the first day, and inhibition reaches steady state between Day 3 and Day 7. Generally in about 5 days.

So around 3-7 days! :)

-Thomas