Atorvas Drug Interactions

The most serious consequence of drug interactions with statins is the development of myopathy or rhabdomyolysis. Drugs that can cause myopathy when given alone increase the risk of myopathy with all statins; these drugs include fibric acid derivatives (fibrates or gemfibrozil), and nicotinic acid. The risk of myopathy is also increased by drugs that increase plasma levels of statins by inhibiting their metabolism. Since the statins have different metabolic pathways, these interactions depend on the individual drug concerned. Atorvastatin is metabolized by the cytochrome P450 isoenzyme CYP3A4 and interactions may occur with drugs that inhibit this enzyme, including ciclosporin, itraconazole, ketoconazole, erythromycin, clarithromycin, HIV-protease inhibitors, nefazodone, amiodarone, and verapamil; there may also be similar interaction with grapefruit juice Such combinations should be used with caution, if at all. Statins may also have effects on other drugs. Bleeding and increases in prothrombin time have been reported in patients taking statins with coumarin anticoagulants.
Antibacterials: Erythromycin and other macrolides are inhibitors of the cytochrome P450 isoenzyme CYP3A4 and may increase plasma concentration and the risk of myopathy with some statins. Rifampicin has been reported to reduce plasma concentration of Atorvastatin.
Anticoagulants: Bleeding and increased prothrombin time in patients receiving oral anticoagulants with statins.
Antifungals: Itraconazole and ketoconazole may increase plasma concentrations and the risk of myopathy with some statins.
Antivirals: HIV-protease inhibitors may increase plasma concentrations of statins.
Calcium-channel blockers: Rhabdomyolysis and hepatitis have been reported in a patient receiving Atorvastatin with diltiazem.
Grapefruit juice: May increase plasma concentration of Atorvastatin.
Immunosuppressants: Reports of myopathy and rhabdomyolysis in patients receiving Atorvastatin with ciclosporin.
Lipid regulating drugs: Myopathy and myositis are adverse effects of statins and fibric acid derivatives including fibrates, gemfibrozil, also with nicotinic acid.
Proton pump inhibitors: Reduction in the first pass metabolism of Atorvastatin due to the inhibition of p-glycoprotein by esomeprazole.