CYP3A4 and myopathy: , 7 The incidence of myopathy is typically ∼1 per 10 000 person-years with standard statin regimens (such as simvastatin 40 mg daily), but factors that increase blood statin levels—such as higher statin doses, concomitant use of certain drugs (e.g. strong CYP3A4 inhibitors, amiodarone), Chinese ethnicity,10 and SLCO1B1 genotype11 , 12—can increase the risk.5