[Marked creatine-phosphokinase elevation in myopathy after treatment with bezafibrate]

Bezafibrate is a fibric acid derivative which has been widely used in the past 15 years. Recent studies have elucidated much of its mechanism of action, which mainly results in reduction of VLDL and triglyceride levels and in elevation of HDL. The drug is relatively safe and its side-effects well known, mild, and reversible. The most severe side-effect is myositis, varying from mild flu-like symptoms to rhabdomyolysis, which is extremely rare. The underlying situations most frequently associated with bezafibrate-induced myositis are renal insufficiency and concomitant treatment with certain other drugs. We describe 2 women who developed severe myositis with bezafibrate treatment. 1, aged 43, who had moderate diabetes but no renal insufficiency, was treated with metformin and warfarin, which can interact with bezafibrate and affect its metabolism. The other, aged 54, had renal insufficiency and was on home peritoneal dialysis. Her bezafibrate dose had been increased because of very high triglyceride levels. The aim of the study is to call attention to this significant side-effect of benzafibrate and to ways of preventing it.