Keep an eye on Carefully (one)pentobarbital will minimize the extent or outcome of fentanyl transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Keep track of Closely. Coadministration of fentanyl with CYP3A4 inducers could lead to some lower in fentanyl plasma concentrations, deficiency of efficacy or, possibly, dev