Watch Carefully (1)lenacapavir will raise the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism.etravirine will lessen the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Stay clear of or Use Alternate Drug. Coadministration of fentanyl with CYP3A4 inducers may lead to your mi