Rifcin Rifampicin Istradefylline
MajorRifampicin is a strong CYP3A4 inducer, so taking it with Istradefylline should be avoided. (With strong CYP3A4 inhibitors like ketoconazole, the maximum dose is 20 mg once daily.)
These medicines can affect each other in a serious way. Do not start taking them together unless your doctor has said it is OK. If you already take both, do not stop either one on your own: speak to your doctor or pharmacist soon.