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 E 2 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 E 2 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.