Hypersensitivity to barbiturates or any element on the formulation; ; background of manifest or latent porphyria butabarbital will minimize the level or outcome of estrogens esterified by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. butabarbital will lower the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Small/Imp... https://ingmars109bfk3.mappywiki.com/user