phenobarbital will lower the level or impact of diazepam buccal by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Watch. Strong or moderate CYP3A4 inducers could improve level of diazepam elimination; as a result, efficacy of diazepam can be lowered.Barbiturates may perhaps impair the psychological and/or Actual physical skill