Increased plasma conc w/ potent CYP3A4 inhibitors (eg, ciclosporin, telithromycin, clarithromycin, delavirdine, stiripentol, ketoconazole, voriconazole, itraconazole, posaconazole), some HCV antivirals (eg, elbasvir/grazoprevir), & HIV PIs including ritonavir, lopinavir, atazanavir, indinavir, darunavir; moderate CYP3A4 inhibitors (eg, erythromycin, diltiazem, verapamil, fluconazole). Increased risk of myopathy w/ erythromycin. Co-administration w/ amiodarone & verapamil may result in increased exposure to atorvastatin. Reduced plasma conc w/ CYP3A4 inducers (eg, efavirenz, rifampin, St. John's wort). Increased systemic exposure w/ transport protein inhibitors (eg, ciclosporin, letermovir). Increased risk of muscle-related events including rhabdomyolysis w/ gemfibrozil/fibric acid derivatives & ezetimibe. Lower plasma conc of atorvastatin & its active metabolites w/ colestipol co-administration. Increased risk of myopathy including rhabdomyolysis w/ systemic fusidic acid. Reports of myopathy w/ colchicine. Slightly increased steady-state conc of digoxin. Increased plasma conc of norethindrone & ethinyl estradiol. Small decrease in prothrombin time w/ warfarin.