Celecoxib Does Not Attenuate the Antiplatelet Effects of Aspirin and Clopidogrel in Healthy Volunteers

Background and Objectives: The prevalence of arthritis, which is often treated with celecoxib, is high in patients with coronary artery disease. Furthermore, celecoxib has been reported to reduce restenosis after coronary stenting by inhibiting expression of the proto-oncogene Akt. A concern is that celecoxib increases thrombogenicity by inhibiting the synthesis of prostacyclin in endothelial cells. However, it is not known whether the administration of celecoxib will attenuate the antiplatelet effects of aspirin and clopidogrel, which are used after stenting. We addressed this gap in our knowledge. Subjects and Methods: We recruited healthy volunteers (n=40) and randomized them into five subgroups (n=8 for each group: aspirin, celecoxib, aspirin+celecoxib, aspirin+clopidogrel, and aspirin+clopidogrel+celecoxib). Each subject received their medications for 6 days and blood samples were taken on day 0 and day 7. Celecoxib (200 mg twice a day), and/or aspirin (100 mg daily), and/or clopidogrel (75 mg daily) were administered. We compared platelet function among subgroups using light transmittance aggregometry and arachidonic acid metabolite assays. Results: Celecoxib treatment alone did not significantly affect platelet aggregation. The reduction in adenosine diphosphase (ADP)-induced platelet aggregation by aspirin+clopidogrel was not affected by addition of celecoxib (31.3${\pm}$6.9% vs. 32.4${\pm}$12.2%, p=0.83). Inhibition of collagen-induced platelet aggregation by aspirin+clopidogrel was not affected by addition of celecoxib (47.6${\pm}$13.4% vs. 51.6${\pm}$3.7%, p=0.69). Drug-induced changes in prostacyclin and thromboxane levels did not differ among treatment groups. Conclusion: Celecoxib treatment does not interfere with the antiplatelet effects of aspirin or clopidogrel, suggesting that celecoxib can be safely administered in combination with dual antiplatelet therapy in patients with coronary stenting without increased thrombogenicity.