Atorvastatin: Increased risk of myopathy w/ cyclosporine, fibric acid derivatives (gemfibrozil, fenofibrate), lipid-modifying doses of niacin (nicotinic acid), or strong CYP3A4 inhibitors [eg, clarithromycin, erythromycin, HIV PIs (eg, ritonavir, lopinavir), & azole antifungals (eg, itraconazole)]. Increased plasma conc w/ strong CYP3A4 inhibitors (eg, erythromycin, grapefruit juice). Increased bioavailability w/ OATP1B1 inhibitors (eg, cyclosporine). Increased AUC w/ diltiazem. Reduced plasma conc w/ antacid; colestipol; cimetidine; CYP3A4 inducers (eg, efavirenz, rifampin). Significant reduction in atorvastatin plasma conc w/ delayed administration of atorvastatin after administration of rifampin; simultaneous co-administration w/ rifampin is recommended. Increased plasma digoxin conc. Increased AUC values of norethindrone & ethinyl estradiol. Reduced plasma conc of antipyrine. Increased AUC & decreased C
max w/ amlodipine. Amlodipine: Strong CYP3A4 inhibitors (eg, ketoconazole, itraconazole, ritonavir) may increase plasma conc. Closely monitor BP when co-administered w/ CYP3A4 inducers.