Diphedan Phenytoin Tolvaptan
MajorPhenytoin is a CYP 3A inducer. That means it speeds up the CYP 3A pathway the body uses to break down medicines. Other medicines in this group include rifampin, rifabutin, rifapentin, barbiturates and carbamazepine. If you take phenytoin with Tolvaptan (Tolvan), less Tolvaptan stays in your blood, so it may not work as well. You should avoid taking these medicines together.
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.