Pentobarbital will decrease the level or effect of prednisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. pentobarbital will decrease the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. When barbiturates like Nembutal are abused, they are not usually the primary drug of abuse. Like https://bookmarkcolumn.com/story20106492/un-imparziale-vista-pentobarbital-icp