Gemfibrozil markedly increases levels of atorvastatin,
pravastatin,
rosuvastatin and
simvastatin. Because of the increased risks of muscle
toxicity (e.g. myopathy or rhabdomyolysis) it is generally accepted that use of a statin in conjunction with a fibrate should only be undertaken if the benefits outweigh the risks. The
incidence of statin/fibrate interactions leading to myopathy may be up to 5%.
Creatine kinase levels should be measured before initiation. Patients taking
statins should be counselled regarding myopathy (e.g. report any unexplained muscle pain, tenderness or weakness). This should be reinforced if they are also given a fibrate. The manufacturers of
rosuvastatin contraindicate doses of 40 mg and above with fibrates, and the manufacturers of
simvastatin contraindicate doses of
above 10 mg daily with
gemfibrozil. The manufacturers of
simvastatin also suggest that doses of greater than 10 mg daily should only be used with other
fibrates (except fenofibrate) if the benefits outweigh the risks of treatment.