Butabarbital will decrease the extent or outcome of zaleplon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Small/Significance Unfamiliar. butabarbital will lower the extent or effect of carvedilol by impacting hepatic enzyme CYP2C9/10 metabolism. Use Warning/Check. butabarbital will lessen the extent or result of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 meta... https://erica677pmh4.wikinstructions.com/user