Pentobarbital will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. pentobarbital will decrease the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. pentobarbital decreases effects of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabo... https://sociallytraffic.com/story5262339/i-pentobarbital-icp-diaries