Pentobarbital will decrease the level or effect of losartan by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown. pentobarbital decreases levels of elvitegravir/cobicistat/emtricitabine/tenofovir DF by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. May lead to loss of virologic response and possible resistance. pentobarbital will decrea... https://madesocials.com/story5809442/the-ultimate-guide-to-pentobarbital-de-sodium