Treatment of symptomatic rectovaginal endometriosis with an estrogen-progestogen combination versus low-dose norethindrone acetate

Objective: To evaluate the efficacy, safety, and tolerability of an estrogen-progestogen combination versus low-dose norethindrone acetate in the treatment of persistent pain after surgery for symptomatic rectovaginal endometriosis. Design: Randomized controlled trial. Setting: Academic center. Patient(s): Ninety women with recurrent moderate or severe pelvic pain after unsuccessful conservative surgery for symptomatic rectovaginal endometriosis. Intervention(s): Twelve-month, continuous treatment with oral ethinyl E 2, 0.01 mg, plus cyproterone acetate, 3 mg/day, or norethindrone acetate, 2.5 mg/day. Main Outcome Measure(s): Degree of satisfaction with therapy. Result(s): Seven women in the ethinyl E2 plus cyproterone acetate arm and five in the norethindrone acetate arm withdrew because of side effects (n=5), treatment inefficacy (n=6), or loss to follow-up (n=1). At 12 months, dysmenorrhea, deep dyspareunia, nonmenstrual pelvic pain, and dyschezia scores were substantially reduced without major between-group differences. Both regimens induced minor unfavorable variations in the serum lipid profile. According to an intention-to-treat analysis, 28 (62%) out of 45 patients in the ethinyl E2 plus cyproterone acetate group and 33 (73%) out of 45 in the norethindrone acetate group were satisfied with the treatment received. Conclusion(s): Low-dose norethindrone acetate could be considered an effective, tolerable, and inexpensive first-choice medical alternative to repeat surgery for treating symptomatic rectovaginal endometriotic lesions in patients who do not seek conception.