Rhabdomyolysis and acute renal failure due to combination therapy with simvastatin and warfarin.

Simvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, is widely used to treat hyperlipidaemia. Although myalgias are recognized adverse effects, clinically significant elevations in serum creatine phosphokinase (CPK) levels are uncommon. We describe a case of rhabdomyolysis and acute renal failure associated with concomitant use of simvastatin and warfarin. Rhabdomyolysis and renal failure occurred 7 days after warfarin (5 mg day-1) was added to a chronic stable dose of simvastatin (20 mg day-1) and resolved abruptly after discontinuation of simvastatin. We recommend careful monitoring when warfarin is given to patients receiving simvastatin.