The
fibrates increase the effects of oral anticoagulants. This has been reported with: bezafibrate and acenocoumarol, phenprocoumon or warfarin; ciprofibrate and warfarin;
clofibrate and phenindione or warfarin;
fenofibrate and acenocoumarol or warfarin, and with
gemfibrozil and
warfarin. There have been fatalities as a result of this interaction.
With
clofibrate, dosage reductions of one-third to one-half may be needed to avoid the risk of bleeding. Monitor the INR and adjust the dose accordingly. Less is known about
fenofibrate and even less about bezafibrate, ciprofibrate and
gemfibrozil but it would be prudent to follow the same precautions suggested for
clofibrate if any of them is used with any oral anticoagulant.