pentobarbital will decrease the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.pentobarbital will decrease the level or effect of fentanyl samhälle affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with CYP3A4 inducers cou