Combination of atorvastatin and gemfibrozil plus physical activity: an animal model of statin/fibrate-induced myopathy.

INTRODUCTION Drug-induced myopathy is among the most common causes of muscle disease. Lipid-lowering drugs, primarily the statins as inhibitors of the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, are a common cause of myopathy. Statin-fibrate combination potentially increases risk for myopathy and rhabdomyolysis. Blood levels of the enzymes creatine kinase (CK), aldolase and lactate dehydrogenase (LDH) increase during myopathy. Exercise may be a trigger for statin-associated muscle symptoms (SAMS). METHODS In this study a model of myopathy induction was designed via combination of oral atorvastatin, gemfibrozil and exercise for ten days in rats. To maximise exercise, the rats were placed in a pool of water and allowed to swim before sinking in the last three days. Finally, the mean of swimming tolerance times and blood levels of creatine kinase, aldolase and lactate dehydrogenase were measured. RESULTS The results showed a significantly (p < 0.05) decreased swimming tolerance time and elevated enzyme levels in rats receiving atorvastatin (ATV) and gemfibrozil (GMF) plus exercise compared with those rats in other groups. This animal model can be used to evaluate the effects of medication on reduction of statin/fibrate-induced myopathy.