Colchicine-induced acute myopathy in a patient with concomitant use of simvastatin.

Colchicine and 3-hydroxy-3-methy-glutaryl coenzyme A (HMG-CoA) reductase inhibitors are well known to cause myopathy. Myotoxicity is dose-dependent in both drugs; therefore, the onset of symptoms usually takes months or years. We report the case of a patient with chronic renal failure who had been taking simvastatin for 2 years and developed acute weakness 2 weeks after the start of treatment with colchicines for recurrent gout. The electromyography and elevated muscle enzymes indicated that his symptoms were caused by myopathy. When this patient stopped taking both drugs, his weakness resolved rapidly. Acute myopathy induced by combination therapy with colchicines and simvastatin is rare. In patients with chronic renal failure, co-administration of colchicine with simvastatin may accelerate the onset of myopathy because CYP3A4 (part of cytochrome P450) is crucial in the breakdown of both drugs. When adding colchicine to a medication regimen that includes a HMG-CoA reductase inhibitor for patients with renal insufficiency, drugs that are metabolized outside the CYP3A4 system (e.g., fluvastatin and pravastatin) should be selected instead.