THE RISK OF MYOPATHY DURING TREATMENT WITH OTHER DRUGS OF THIS CLASS IS INCREASED WITH CONCURRENT ADMINISTRATION OF CYCLOSPORINE, FIBRIC ACID DERIVATIVES, NIACIN (NICOTINIC ACID), ERYTHROMYCIN, AZOLE ANTIFUNGALS. PLASMA DIGOXIN CONCENTRATIONS INCREASED BY APPROXIMATELY 20%. PLASMA CONCENTRATIONS OF ATORVASTATIN INCREASED APPROXIMATELY 40% WITH COADMINISTRATION OF ERYTHROMYCIN. COADMINISTRATION OF ATORVASTATIN AND AN ORAL CONTRACEPTIVE INCREASED AUC VALUES FOR NORETHINDRONE AND ETHINYL ESTRADIOL BY APPROXIMATELY 30% AND 20%. BLEEDING AND INCREASES IN PROTHROMBIN TIME HAVE BEEN REPORTED IN PATIENTS TAKING ATORVASTATIN WITH COUMARIN ANTICOAGULANTS.