Butabarbital will decrease the level or influence of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Intently. The efficacy of hormonal contraceptives could be reduced. butabarbital will lower the level or influence of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metaboli... https://francesb242wly0.azzablog.com/profile