[Effect of the GnRH analog buserelin on sex hormone serum level in relation to treatment onset and duration].

Changes of serum estradiol, progesterone, LH, FSH, prolactin, testosterone, androstendione, DHEA and DHEAS levels during a GnRH-analogue (buserelin) treatment have been analysed retrospectively taking account of effectiveness of treatment and its relation to the beginning and duration of treatment. 1200 micrograms/day buserelin were administered intranasally from the first day of the menstrual cycle (n = 30) or the 7th hyperthermic day of the cycle (n = 22). The results proved, that the administration of buserelin to sterile women inhibits the ovarian (estradiol, progesterone) and pituitary (LH, FSH) hormone secretion during the first 10-14 days of treatment. The adrenal hormone secretion (DHEA, DHEAS) remained unaffected, whereas the androgens of ovarian origin (testosterone, androstendione) were suppressed during the GnRH analogue treatment. The serum prolactin level increased during the first two weeks of treatment and returned to pretreatment values within the following two weeks. On the basis of the faster suppression of estradiol secretion with buserelin treatment, beginning in the middle of the luteal phase, this therapy is recommended for ovarian suppression.