Mizoribine-induced rhabdomyolysis in a rheumatoid arthritis patient receiving bezafibrate treatment

Bezafibrate, one of fibric acid derivatives, is widely used to treat hypertriglyceridemia and diabetic dyslipidemia. Fibric acid derivatives are known to induce rhabdomyolysis as a side effect, especially when given to patients with renal dysfunction. Mizoribine, an imidazole nucleoside, is used as an immunosuppressive agent. Here, we present a case of a patient with rheumatoid arthritis who developed rhabdomyolysis while undergoing treatment with mizoribine concomitantly with bezafibrate. Drug-induced rhabdomyolysis was suspected and bezafibrate and mizoribine were discontinued, and the patient was treated with hydration. The patient's symptoms rapidly disappeared and abnormalities of blood and urine test findings also improved to normal levels within 1 week. When prescribing fibrates to patients with high risk of renal damage, caution should be exercised regarding interactions with other drugs and the potential for inducing rhabdomyolysis.