Hypersensitivity to barbiturates or any part on the formulation; ; background of manifest or latent porphyria butabarbital will lessen the extent or result of carvedilol by influencing hepatic enzyme CYP2C9/10 metabolism. Use Caution/Watch. butabarbital will decrease the level or result of pimozide by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Importance Unidentified. https://janetf013bxj3.ttblogs.com/profile