Celecoxib does not affect the antiplatelet activity of aspirin in healthy volunteers.

Celecoxib is a novel cyclooxygenase-2-specific inhibitor for the management of acute pain, primary dysmenorrhea, and the signs and symptoms of arthritis. This double-blind, placebo-controlled study in 16 healthy volunteers evaluated whether celecoxib alters the effect of concomitant aspirin on platelet function. Volunteers received celecoxib (400 mg/day) or placebo for 4 days. On day 5, they also received a single 325 mg dose of aspirin with either 200 mg celecoxib or placebo. Thromboxane and platelet aggregation response to adenosine 5′-diphosphate (ADP), collagen, and arachidonic acid were measured before the first dose of celecoxib or placebo (baseline) and before dosing and 2 and 8 hours postdose on day 5. There was no significant difference in thromboxane inhibition between the two groups (percent inhibition: placebo 99.4%, celecoxib 99.0%; p = 0.555). There was also no significant difference in the effect of aspirin on platelet aggregation due to ADP, collagen, or arachidonic acid between the groups. Therefore, these data indicate that celecoxib does not alter the effects of aspirin on platelet function.