Observe Carefully (3)pentobarbital will decrease the level or effect of diazepam intranasal by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Check. Solid or moderate CYP3A4 inducers could improve amount of diazepam elimination; for that reason, efficacy of diazepam could be diminished.pentobarbital will lessen the extent or inf