Long-acting gonadotropin hormone-releasing hormone analog used to treat uteri

Because the size of leiomyomata uteri often decreases significantly after menopause, the authors elected to employ a long-acting gonadotropin hormone-releasing hormone analog (GnRH-a) (imbzl-D-His⁶-Pro⁹-Net-GnRH) to create a state of pseudomenopause in six patients with leiomyomata uteri diagnosed on the basis of pelvic examination and confirmed by pelvic ultrasonography. Patients received daily, subcutaneous injections of GnRH-a (4 μg x kg^-1 x 24 hour^-1) for 6 months. Uterine size (13.8 ± 4 weeks [mean ± standard deviation (SD), n = 6] was determined by pelvic examination and uterine volume (533.9 ± 394 ml [mean ± SD, n = 6]) was determined by pelvic ultrasonography before medical therapy was begun. They observed a decrease in uterine size by pelvic examination within 4 weeks of the initiation of therapy, and all patients experienced a decrease in uterine size (9.5 ± 4 weeks [mean ± SD, n = 6]) (P<0.05) within 8 weeks of initiation of therapy. After 6 months of therapy, uterine size was 229.5 ± 145 ml (mean ± SD, n = 6). During treatment, plasma estrogen concentrations were assessed intermittently (every 1 to 4 weeks) and remained <4 pg x ml^-1 throughout the period of therapy. All six patients have discontinued therapy. There has been no increase in uterine size in these patients for a period from 3 to 7 months. The authors conclude that administration of a long-acting GnRH-a appears to be a practical method for reducing the size of uterine leiomyomata and may serve a useful role either as a primary means of therapy or as an adjunct to surgical myomectomy, especially in patients with exceedingly large myomas who wish to conserve reproductive capability.