butabarbital will reduce the level or impact of fedratinib by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Influence of coadministering a solid CYP3A4 inducer with fedratinib has not been studied.butabarbital will lower the extent or result of midazolam by influencing hepatic/intestinal enzyme CYP3A4 metabol