pentobarbital will lower the extent or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Watch.pentobarbital decreases levels of vandetanib by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Stay clear of coadministration with powerful CYP3A4 inducers; these drugs lessen publicity… Read More