butabarbital will lessen the level or influence of fedratinib by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Impact of coadministering a powerful CYP3A4 inducer with fedratinib has not been examined.butabarbital will minimize the level or effect of aprepitant by influencing hepatic/intestinal enzyme CYP3A4