Lack of interaction of ketoprofen with warfarin.

We gave ketoprofen (100 mg bid) for 7 days, on a placebo-controlled, double-blind basis, to 15 healthy male volunteers already stabilized on warfarin in dosages which lowered the prothrombin time by about 60%. Ketoprofen did not affect the prothrombin time, there was no change in coagulation cascade parameters, and there was no clinical evidence of bleeding. We conclude that ketoprofen in this dosage has no significance effect on the anticoagulant effect of warfarin.