May increase simvastatin plasma conc & may lead to increased risk of myopathy w/ transport protein OATP1B inhibitors; BCRP inhibitors (eg, elbasvir, grazoprevir). Increased risk of myopathy in concomitant use w/ potent CYP3A4 inhibitors (eg, itraconazole, ketoconazole, posaconazole, voriconazole, erythromycin, clarithromycin, telithromycin, HIV-PIs, boceprevir, telaprevir, nefazodone, cobicistat). Concomitant use is contraindicated w/ gemfibrozil, cyclosporine or danazol. Risk of myopathy may be increased by moderate CYP3A4 inhibitors. Cholesterol excretion into the bile may be increased by fibrates, leading to cholelithiasis. May increase risk of myopathy/rhabdomyolysis by fusidic acid; lomitapide. Increased risk of myopathy/rhabdomyolysis by amiodarone; verapamil, diltiazem, amlodipine; niacin (≥1 g daily); daptomycin. Decreased mean AUC of ezetimibe by cholestyramine. Possible myopathy/rhabdomyolysis in patients w/ renal insufficiency when concomitantly administered w/ colchicine. HMG-CoA reductase inhibitory activity may significantly be increased by grapefruit juice (large quantities). Modestly potentiated coumarin anticoagulants effects by simvastatin.