Butabarbital will decrease the level or impact of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Result of coadministering a strong CYP3A4 inducer with fedratinib has not been studied. butabarbital will decrease the extent or influence of vardenafil by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Observe. https://englandi101tbl4.vblogetin.com/profile