mavacamten will reduce the extent or result of ethinylestradiol by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Stay clear of or Use Alternate Drug. Progestin and ethinyl estradiol are CYP3A4 substrates. Mavacamten could decrease systemic exposures of ethinyl estradiol and progestin, which can produce contraceptive failure or a rise in