butabarbital will lessen the level or effect of amlodipine by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Watch.butabarbital will decrease the level or effect of glecaprevir/pibrentasvir by influencing hepatic/intestinal enzyme CYP3A4 metabolism.butabarbital will decrease the level or influence of hydrocortisone by affecting