Mavacamten will lower the extent or influence of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Progestin and ethinyl estradiol are CYP3A4 substrates. Mavacamten may well reduce systemic exposures of ethinyl estradiol and progestin, which can lead to contraceptive failure or an increase in breakthrough bleeding. https://charlesn627mme8.robhasawiki.com/user