pentobarbital decreases amounts of elvitegravir/cobicistat/emtricitabine/tenofovir DF by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Could result in loss of virologic reaction and doable resistance.pentobarbital will decrease the extent or impact of lopinavir by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Us