pentobarbital will lessen the extent or result of fentanyl intranasal by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Keep an eye on Intently. Coadministration of fentanyl with CYP3A4 inducers could lead on to the lessen in fentanyl plasma concentrations, deficiency of efficacy or, possibly, advancement of a withdrawal sy