Observe Intently (one)phenobarbital will minimize the extent or effect of fentanyl transmucosal by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Keep track of Closely. Coadministration of fentanyl with CYP3A4 inducers could lead on to a reduce in fentanyl plasma concentrations, lack of efficacy or, potentially, advancement… Read More