Tell your doctor about all your other medicines, especially:
cyclosporine;
ketoconazole;
warfarin (Coumadin, Jantoven);
an antibiotic--clarithromycin, erythromycin;
antiviral medicine--ritonavir, saquinavir; or
heart or blood pressure medicine--amiodarone, quinidine, verapamil.
This list is not complete. Other drugs may affect rifaximin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.
 Rifaximin drug interactions (more detail)
