Butabarbital will minimize the extent or outcome of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Observe Carefully. The efficacy of hormonal contraceptives may very well be reduced. butabarbital will lower the level or influence of levamlodipine by influencing hepatic/intestinal enzyme CYP3A4 metabol... https://jasonr653swz8.blognody.com/profile