phenobarbital will decrease the level or impact of diazepam buccal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Observe. Potent or average CYP3A4 inducers may raise level of diazepam elimination; therefore, efficacy of diazepam may very well be lessened.Hypnotic doses of barbiturates tend not to look to impair uterine actio