. . . "Make sure your doctor knows if you are also using carbamazepine (Tegretol??), clarithromycin (Biaxin??), erythromycin (Ery-Tab??), itraconazole (Sporanox??), ketoconazole (Nizoral??), phenobarbital (Luminal??), rifampin (Rifadin??, Rimactane??), ritonavir (Norvir??), St. John's wort, or a blood thinner such as warfarin (Coumadin??)." .