Influence of danazol treatment during the luteal phase on pituitary and ovarian function during the subsequent menstrual cycle.

Eight subjects with normal menstrual cycles were treated with danazol (800 mg daily) during one luteal phase to assess the effect on follicular development in the subsequent cycle. Plasma levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, and progesterone were measured daily throughout both cycles. Following danazol there was a consistent and significant delay to the preovulatory estradiol (P less than 0.05) and LH (P less than 0.02) peaks and a significant suppression of the early follicular phase FSH (P less than 0.05) and preovulatory estradiol peak plasma levels (P less than 0.05). All other parameters of the post-danazol cycle were indistinguishable from normal. However, there was a small suppression of midluteal phase FSH during danazol treatment, compared with the posttreatment cycle, which was significant for three subjects. It is suggested that the small effect of luteal phase danazol on subsequent follicle development may occur at an intraovarian level through an effect on receptors or enzymes as well as through the small degree of suppression of midluteal phase and early follicular phase FSH.