pentobarbital will decrease the level or effect of oxybutynin ort affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.pentobarbital will decrease the level or effect of diazepam buccal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Skärm. Strong or moderate CYP3A4 inducers may increase rate of d