The effects of combining norethindrone with a gonadotropin-releasing hormone agonist in the treatment of symptomatic endometriosis.

Treatment of endometriosis with gonadotropin-releasing hormone agonists (GnRH-a) is associated with side effects secondary to the induced hypoestrogenic state. In an effort to ameliorate these symptoms, 10 patients with symptomatic endometriosis self-administered the GnRH-a [D-His6(Imbzl)-Pro9-NET]-GnRH in combination with norethindrone daily for 24 weeks. Painful symptoms were significantly suppressed after therapy (P less than 0.005). Objective review of photographs taken at laparoscopy before and after therapy demonstrated significant reduction of visible implants (P less than 0.005). Vasomotor symptoms were minimized when compared with a group of 16 patients previously treated with GnRH-a alone. Bone mineral density of the distal radius assessed by single photon absorptiometry was not reduced during therapy, although lumbar spine bone density assessed by quantitative computerized tomography was minimally but reversibly reduced. No metabolic derangements were detected. The combination of norethindrone with GnRH-a is a well tolerated and effective means of treating symptomatic endometriosis.