Pharmacodynamic Effects When Clopidogrel is Given Before Cangrelor Discontinuation

To determine whether initiation of clopidogrel before discontinuation of cangrelor would impact on the recovery of platelet reactivity.

The active metabolite of clopidogrel cannot bind to P2Y12 when cangrelor occupies the receptor. Pharmacodynamic studies have shown that this interaction is avoided when clopidogrel is given at the end of the cangrelor infusion. We found that antiplatelet effects of another thienopyridine, prasugrel, were apparent when prasugrel was administered 0.5 hour before cangrelor was stopped.

Platelet function studies (light transmission aggregometry, VerifyNow, and flow cytometry) were performed on blood from patients with stable coronary artery disease who were taking aspirin when a loading dose of clopidogrel (600 mg) was given during a cangrelor infusion (0.5 and 1 hour before cangrelor was stopped). Results were compared with those obtained when clopidogrel was given immediately after cangrelor was stopped.

Administration of clopidogrel 0.5 and 1 hour before discontinuation of the cangrelor infusion did not prevent recovery of platelet reactivity more effectively than administration at the end of the infusion.

Our results support the previously established strategy of administering clopidogrel immediately after discontinuation of cangrelor. Earlier administration increases the recovery of platelet function.