pentobarbital will lower the extent or influence of voriconazole by influencing hepatic enzyme CYP2C9/ten metabolism. Small/Importance Unidentified.pentobarbital will minimize the extent or outcome of fentanyl by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Keep an eye on Closely. Coadministration of fentanyl with CYP3A4 in