pentobarbital will lessen the extent or effect of fentanyl by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Keep an eye on Carefully. Coadministration of fentanyl with CYP3A4 inducers may lead into a decrease in fentanyl plasma concentrations, not enough efficacy or, potentially, enhancement of a withdrawal syndrome in a ver… Read More