Monitor Closely (1)pentobarbital will decrease the level or influence of fentanyl by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Keep track of Intently. Coadministration of fentanyl with CYP3A4 inducers could lead to some lower in fentanyl plasma concentrations, insufficient efficacy or, possibly, enhancement of the with… Read More