pentobarbital will lower the level or influence of montelukast by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Importance Mysterious.pentobarbital decreases amounts of elvitegravir/cobicistat/emtricitabine/tenofovir DF by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. May possibly produce lack of virolog