Fenofibrate Warfarin

Kim KY, Mancano MA. Fenofibrate potentiates warfarin effects. Ann Pharmacother 2003 37 212-5. 

Several interactions between warfarin and hypohpidemic drugs have been described (SEDA-21, 459), including clinically important potentiation of warfarin by bezafibrate (73) and gemfibrozil (74). Two patients developed a significantly increased anticoagulant effect of warfarin while taking fenofibrate (75). 

Ascah KJ, Rock GA, Wells PS. Interaction between fenofibrate and warfarin. Ann Pharmacother 1998 32(7-8) 765-8. 

Fibric adds Clofibrate Gemfibrozil Fenofibrate Increase VLtt-catabolism PPAR , agonist LDLi 5-20% HDL t 10%-20% TG i 20%-S0% Gl upset, dyspepsia, gallstones, T LFTs, myopathy Nonmetabolism Warfarin Cyclosporine Statins Liver or severe renal disease primary biliary cirrhosis preexisting gallbladder disease... 

A patient taking warfarin had a rise in his INR to 8.5 (from a previous range of 2 to 2.5) within a week of starting to take fenofibrate 200 mg daily. His INR later restabilised when the warfarin dosage was reduced by 27%. 

A patient taking warfarin bled, and was found to have an INR of 18 when his gemfibrozil was replaced by fenofibrate. ... 

In 2 cases 30 to 40% reductions in the warfarin dose were required when fenofibrate was given. ... 

A 71-year-old man with type 2 diabetes taking amlodipine, warfarin, valsartan, hydrochlorothiazide, atenolol, and rosiglitazone was given fenofibrate. The HDL cholesterol fell from 0.96 to 0.60 mmol/1 but rose to 0.80 mmol/1 on changing the rosiglitazone to pioglitazone. 

A 64-year-old woman with type 2 diabetes taking metoprolol aspirin, niacin, warfarin, simvastatin, rosiglitazone, and metformin was given fenofibrate. The HDL cholesterol fell from 1.09 to 0.44 mmol/1. The fenofibrate was withdrawn and the HDL rose to 1.09 mmol/1. 

---