Pentobarbital will decrease the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. pentobarbital will decrease the level or effect of levoketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown. When barbiturates like Nembutal are abused, they are not usually the primary drug of ... https://socials360.com/story10838796/considerazioni-da-sapere-su-soluzione-orale-di-nembutal