Treatment of leiomyomata with intranasal or subcutaneous leuprolide, a gonadotropin-releasing hormone agonist.

Fourteen premenopausal women with uterine leiomyomata were randomized to receive a gonadotropin-releasing hormone agonist (GnRH-a), leuprolide, either by daily subcutaneous (SC) injection (500 micrograms/day) or by intranasal (IN) spray (1600 micrograms/day) for 24 weeks. In the SC group, a significant reduction in uterine volume occurred from a pretreatment volume of 368 +/- 60 (mean +/- standard error of the mean [SEM]) cm3 to 202 +/- 61 cm3 at 12 weeks of therapy (P less than 0.01) and to 172 +/- 49 cm3 at 24 weeks of therapy (P less than 0.005). In the IN group, no significant reduction in uterine volume occurred. In addition, there was a significant negative correlation between the serum estradiol concentration during treatment and the percent decrease in uterine volume (r = -0.55, P less than 0.05). Four months after completing therapy, uterine volume increased to 296 +/- 104 cm3 in the SC group, which was not significantly different from pretreatment volume. These findings suggest that reduction in uterine volume depends on the degree of hypoestrogenism induced and that uterine volume increases soon after cessation of GnRH-a therapy.