mavacamten will decrease the level or outcome of ethinylestradiol by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Progestin and ethinyl estradiol are CYP3A4 substrates. Mavacamten could minimize systemic exposures of ethinyl estradiol and progestin, which can bring about contraceptive failure or a rise in br… Read More