Clinical study of possible interactions between indoprofen and oral anticoagulants.

Possible interactions between indoprofen (IP) and Warfarin Na (W) were studied in 18 patients under chronic anticoagulant treatment, according to a cross-over, double-blind design, comparing 600 mg daily of IP with placebo (PL). In all subjects the dosage of W was kept constant throughout the study (21 days). No significant differences were found between IP and PL either on coagulation parameters or on platelet count and platelet adhesiveness. Afte IP a significant decrease in platelet aggregation (induced by ADP and adrenaline) was observed. The results suggest that indoprofen can be administered to patients under anticoagulant treatment, although frequent checks of the coagulation parameters are advisable in these cases.