pentobarbital will lower the level or impact of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Keep track of.pentobarbital will lessen the level or effect of fentanyl intranasal by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Watch Carefully. Coadministration of fentanyl with CYP3A4 induc