 [ Symptoms ] diazepam interaction with oxcarbazepine  i have read conflicting information one site say is trileptal lowers valium the other say is it increases its effect valium has both the cyp450 2c19 isoenzyme and hepaticintestinal enzyme cyp3a4 metabolism the cyp450 2c19 increases blood plasma of valium but cyp3a4 decreases it i found this when i was trying to find why i may have felt major anxiety on this new med trileptal is it decreasing my anxiety medication  thanks in advance [ Disease ] hi this is from www drugs com oxcarbazepine may increase the blood levels and effects of diazepam you may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications contact your doctor if you experience increased side effects or your condition changes it is important to tell your doctor about all other medications you use including vitamins and herbs do not stop using any medications without first talking to your doctor hope it helps you good luck