MEDROXYPROGESTERONE ACETATE SUPPLEMENTATION DIMINISHES THE HYPOESTROGENIC SIDE-EFFECTS OF GONADOTROPIN-RELEASING-HORMONE AGONIST WITHOUT CHANGING ITS EFFICACY IN ENDOMETRIOSIS

Objective: To examine the effects of concomitant use of goserelin and medroxyprogesterone acetate (MPA) in the treatment of endometriosis. D esign: Thirty-eight women with laparoscopically confirmed endometriosi s were treated with once-a-month SC injections of goserelin acetate 3. 6 mg (Zoladex depot; Zeneca Pharmaceutics, Cheshire, United Kingdom) r andomly combined with either MPA (100 mg daily; n = 19) or a placebo ( one tablet daily; n = 19) in a double-blind trial. Symptoms and side e ffects were monitored for a treatment period of 6 months and a follow- up period of 6 months. Blood and urine samples were collected for the assessment of endocrine and biochemical parameters. A second-look lapa roscopy was performed 6 months after the treatment in 29 women.Results : The extent of endometriosis was diminished similarly in both treatme nt groups, as were pelvic symptoms. Fewer women in the MPA group had h ot flushes and sweating at 3 and 6 months of treatment. Sex hormone-bi nding globulin decreased in the MPA group but not in the placebo group . Consequently, the E(2) index (E(2)/SHBG x 100), reflecting the free fraction of E(2), fell more in the placebo group than it did in the MP A group. The increased urinary excretion of calcium observed during pl acebo treatment was prevented by MPA. Conclusion: High-dose MPA combin ed with a GnRH agonist (GnRH-a) diminished some antiestrogenic effects of the agonist. A reduction in hypoestrogenic side effects and a poss ible bone-sparing effect can be regarded as beneficial, especially as the good effect of the GnRH-a on endometriotic implants and pelvic sym ptoms prevailed.