pentobarbital will lower the extent or outcome of fludrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Check.pentobarbital will reduce the extent or influence of tramadol by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Keep track of. Lessened AUC of tramadol along with the Lively metabolite (O-