4 Statin-Induced myotoxicity: An overview of the risk factors

Statins are well tolerated and particularly safe medicines. The most important clinical side effect of statins is myotoxicity. Rhabdomyolysis is the most rare, but most serious of myotoxicity. Clinically it is characterized by proximal or diffuse muscle pain, weakness and myoglobinuria. CPK usually exceeds by far 10 times the upper limit of normal. Factors, which increase the risk of myotoxicity, are: advanced age and female gender (for unknown reasons), genetic polymorphism (low hepatic or intestinal expression of the isoenzyme CYP3A4), hereditary myopathy, lipophilicity of some statins, high doses of statins (dose-dependent side effect), medicines and foods that are metabolized by CYP3A4, renal failure and hepatic dysfunction, as well as the conditions that worsen them.