pentobarbital decreases amounts of elvitegravir/cobicistat/emtricitabine/tenofovir DF by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Could produce loss of virologic reaction and probable resistance.pentobarbital will reduce the extent or result of cinacalcet by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use W