pentobarbital will lower the extent or impact of fedratinib by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Impact of coadministering a solid CYP3A4 inducer with fedratinib hasn't been studied.pentobarbital will lessen the level or impact of bexarotene by impacting hepatic/intestinal enzyme CYP3A4 metabolism.