Danazol: endocrine consequences in healthy women.

We studied the effects of danazol on pituitary and gonadal function in seven normal women who volunteered to take danazol, 400 mg twice daily, for 2 months. We measured circulating levels of sex steroids, gonadotropins, and prolactin on alternate days throughout a control menstrual cycle and during treatment. Danazol inhibited ovulation in all subjects. The amenorrheic state induced by danazol was characterized by normal basal levels of gonadotropins, prolactin, and estrogen. Serum androgen levels were significantly increased as was the urinary excretion of 17-ketosteroids. The LH and FSH responses to gonadotropin-releasing hormone were enhanced during treatment, and there was a normal LH rise following administration of estradiol valerate, indicative of intact positive feedback. These observations fail to support the contention that danazol suppresses pituitary gonadotropin secretion or directly inhibits steroidogenesis. The results suggest that danazol may have a primary site of action at the ovary by suppressing the normal, orderly process of follicular maturation.