mavacamten will decrease the level or influence of ethinylestradiol by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Steer clear of or Use Alternate Drug. Progestin and ethinyl estradiol are CYP3A4 substrates. Mavacamten could lower systemic exposures of ethinyl estradiol and progestin, which can lead to contraceptive failure or an incre… Read More