Which medication would best block feedback inhibition of estradiol, promoting an increase in FSH for a patient with anovulation?

Clomiphene citrate is an important medication used to treat anovulation, especially in cases of polycystic ovary syndrome (PCOS) and other conditions where ovulation is impaired. It functions primarily as a selective estrogen receptor modulator (SERM). By binding to estrogen receptors in the hypothalamus, clomiphene citrate blocks the normal feedback inhibition exerted by estradiol on gonadotropin-releasing hormone (GnRH) secretion. When the body senses lower estrogen levels at the hypothalamic level due to the receptor blockage, it responds by increasing the production of GnRH, subsequently stimulating the anterior pituitary to secrete higher levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

This increase in FSH promotes the growth and maturation of ovarian follicles, encouraging ovulation. Thus, the action of clomiphene citrate directly targets the hormonal imbalances associated with anovulation, providing a clear mechanism to facilitate ovulation.

The other medications listed do not directly block the feedback inhibition of estradiol in the same way. Leuprolide, for example, is a GnRH agonist that initially stimulates gonadotropin release but ultimately leads to decreased