There is increased risk of myopathy if certain drugs are given concurrently with statins. Concomitant administration of drugs that inhibit the cytochrome P450 isoenzyme CYP3A4, such as ciclosporin, itraconazole, ketoconazole, erythromycin, clarithromycin, HIV-protease inhibitors, and nefazodone, might produce high plasma levels of atorvastatin, thus increasing the risk of myopathy.