- Use of prescription or non-prescription drugs that are known to be metabolized in the liver and can potentially interfere with the study medication (such as Marcolide antibiotics, azole antifungals, warfarin, carbamazepine, cyclosporine, midazolam, phenytoin, valporic acid, chlorpromazine, rifampin, quinidine, diazepam and digoxin) 90 days prior to screening.