Moderate
Established
الوصف
Diltiazem inhibits CYP3A4-mediated atorvastatin metabolism, increasing atorvastatin plasma concentrations and the risk of myopathy and rhabdomyolysis.
الآلية
Atorvastatin is primarily metabolised by CYP3A4; diltiazem is a moderate CYP3A4 inhibitor that reduces atorvastatin clearance, raising systemic exposure by approximately 30–50%.
الأهمية السريرية
Higher atorvastatin concentrations increase the risk of muscle toxicity; myalgia, CK elevation, and rhabdomyolysis have been reported.
التدبير
Limit atorvastatin dose to 20 mg/day when combined with moderate CYP3A4 inhibitors; monitor for myalgia and CK elevation; consider switching to pravastatin or rosuvastatin.