What drugs interact with Lipitor and Vytorin?

Lipitor

Decreased elimination of Lipitor could increase levels of Lipitor in the body and increase the risk of muscle toxicity from Lipitor. Therefore, Lipitor should not be combined with drugs that decrease its elimination. Examples of such drugs includes:

Large quantities of grape fruit juice (>1.2 liters daily) also will increase blood levels of Lipitor and should not be taken.

The following drugs also may increase the risk of muscle toxicity when combined with Lipitor.

Lipitor increases the effect of warfarin (Coumadin) and the concentration in blood of digoxin (Lanoxin). Patients taking Lipitor and warfarin or digoxin should be monitored carefully. Cholestyramine (Questran) decreases the absorption of Lipitor. Lipitor should be given at least two hours before and at least four hours after cholestyramine.

Rifampin increases breakdown of Lipitor. To reduce the likelihood of this interaction both drugs should be given at the same time. Lipitor should not be given after rifampin.

Vytorin

Vytorin contains simvastatin (Zocor), and numerous drugs block the elimination of simvastatin by the liver. Decreased elimination of simvastatin could increase the levels of simvastatin in the body and increase the risk of muscle toxicity from simvastatin. Vytorin should not be combined with drugs that decrease its elimination. Examples of these drugs include erythromycin (E-Mycin), ketoconazole (Nizoral), itraconazole (Sporanox), clarithromycin (Biaxin), telithromycin (Ketek), cyclosporine (Sandimmune), nefazodone (Serzone), boceprevir (Victrelis), telaprevir (incivek), voriconazole (Vfend), posaconazole (Noxafil), and HIV protease inhibitors such as indinavir (Crixivan) and ritonavir (Norvir).

Large quantities of grape fruit juice (>1 quart daily) also will increase blood levels of simvastatin and should be avoided.\

Amiodarone (Cordarone), verapamil (Calan Verelan, Isoptin), diltiazem, amlodipine (Norvasc), danazol (Danocrine), ranolazine (Ranexa) cyclosporine (Gengraf, Neoral), niacin (Niacor, Niaspan, Slo-Niacin), gemfibrozil (Lopid) and fenofibrate (Tricor) also may increase the risk of muscle toxicity when combined with simvastatin.

Patients taking amiodarone, amlodipine, or ranolazine should not exceed 10/20 mg, and those taking verapamil or diltiazem should not exceed 10/10 mg of of Vytorin daily.

Patients taking gemfibrozil or danazol should not take Vytorin.

Simvastatin increases the effect of warfarin (Coumadin) and the blood concentration of digoxin (Lanoxin). Patients taking simvastatin and warfarin or digoxin should be monitored carefully. Cholestyramine (Questran) decreases the absorption of ezetimibe, and, therefore, Vytorin should be administer two hours before or at least four hours after cholestyramine is administered.

Chinese patients taking more than 1 gram of niacin daily in combination with simvastatin, 40 mg, have an increased risk of muscle-related side effects. Therefore, these patients should not receive Vytorin 10/80 mg combined with niacin doses greater than 1 gram daily. Other doses of Vytorin should be administered cautiously when combined with niacin, 1 gram daily.