The contraceptive use of Buserelin a potent LHRH agonist: clinical and hormonal findings.

Over 411 treatment months 70 women aged 17 to 42 were given daily intranasal doses of different amounts of Buserelin for fertility control. The main difficulty was finding the threshold dose that has a high antifertility effectiveness combined with low undesirable effects on such target organs as the breast and the endometrium. Data indicate that 200 mcg Buserelin are sufficient for contraceptive effectiveness but the unpredictable behavior of follicular maturation and thus estradiol secretion seems the main problem. Basal secretions of both gonadotropins remained nearly unaltered during the whole treatment course at all dose levels. Intranasal administration of Buserelin evokes a pronounced release of luteinizing hormone follicle stimulating hormone and then estradiol during the 1st day of treatment. The stimulatory effect of Buserelin on gonadotropin secretion clearly decreased and estradiol secretion showed a tendency to low values as treatment progressed. Prolonged estradiol secretion caused marked proliferation of the endometrium and was often not interrupted by withdrawal bleeding. Normal cyclic functions returned after cessation of therapy. Endometrial biopsies in a limited number of cases showed mild proliferation in menstruating women and inactive endometrium in amenorrheal women. The combination of luteinizing hormone-releasing hormone agonists with intermittent use of gestagens as well as the postovulatory induction of luteolysis are suggested.