Effect of danazol on serum concentrations of pituitary gonadotropins in postmenopausal women.

The antigonadotropic action of danazol is still a subject of controversy. Danazol does not cause a consistent and significant suppression of basal gonadotropin concentrations in premenopausal women. In order to investigate the possible effects of danazol on circulating gonadotropin levels in the absence of gonadal feedback, postmenopausal women were studied. Twelve healthy women, at least 3 years past the menopause, volunteered. Their mean age was 61.1 +/- 5.5 (SD) years. Danazol in daily doses of 400, 600 or 800 mg was given randomized, to 4 patients each, for 4 weeks. Venous samples were drawn at -1, 0, +1, +2, +4 weeks of medication. FSH and LH in serum were measured by means of double antibody radio-immunoassay. There was no significant difference between any of the pre-treatment means in the three dose groups. After 4 weeks of danazol treatment, FSH had decreased by 18%, 31%, and 32% in the 400, 600 and 800 mg groups, respectively. The corresponding decreases in LH were 14%, 24% and 21%. There was no significant dose response between any of the doses used. In the absence of significant differences between the pre-treatment means and of significant dose response, data for all 12 patients were pooled for statistical evaluation. The mean decrease in FSH was significant only after 4 weeks (-4.8 micrograms/l; p less than 0.001). The mean decrease in LH was significant after 1, 2 and 4 weeks of treatment (-1.0 to -1.13; p less than 0.01 or less).(ABSTRACT TRUNCATED AT 250 WORDS)