- Use of any of the following within eight weeks prior to screening: potent CYP3A4 inhibitors, cytotoxic agents (including azathioprine, mercaptopurine, cyclosporine, cyclophosphamide, etc.), ranolazine, digoxin, theophylline, sulphonylureas, thiazolidinediones (e.g., rosiglitazone or pioglitazone), desipramine, atypical antipsychotic agents, loop diuretics, warfarin, or phenytoin