The influence of danazol on pituitary function and on the ovarian follicular hormone secretion in premenopausal women.

The purpose of this investigation was to study the influence of danazol on the basal levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), on their response to gonadotropin-releasing hormone (GnRH), as well as the effect of different doses on the serum levels of prolactin, estradiol and progesterone. Three groups of regularly menstruating women were treated with danazol, 600, 400 and 200 mg a day, respectively. Serum samples were obtained--and in the 600 mg group a GnRH-test was performed--before, and after one, 3 and 6 months of continuous medication. LH, FSH, prolactin, estradiol and progesterone were measured by radio-immunoassay. Compared with pretreatment levels in the early follicular phase, basal serum levels of gonadotropins were unchanged during treatment with danazol 600 mg. However, compared with pretreatment levels later on in the menstrual cycle, a slight but significant decrease in LH and increase in FSH were observed. The pituitary responsiveness to GnRH was significantly higher during danazol treatment, than found during the early follicular phase. Serum prolactin levels decreased significantly during treatment with 600 and 400 mg a day, but not with 200 mg a day. The mean estradiol levels on danazol 600 mg a day varied between 153 +/- 9 (SE) and 161 +/- 17 pmol/l, corresponding to the levels in the early follicular phase (100-250 pmol/l). In the lower dose groups, the mean estradiol levels were significantly higher, varying between 265 +/- 30 and 321 +/- 57 pmol/l in the 400 mg group, and between 279 +/- 39 and 405 +/- 125 pmol/l in the 200 mg group.(ABSTRACT TRUNCATED AT 250 WORDS)