Leuprolide Acetate Depot and Hormonal Add-Back in Endometriosis: A 12-Month Study

Abstract

OBJECTIVE: To evaluate the efficacy and safety of a GnRH agonist, leuprolide acetate depot, alone and in combination with three hormonal add-back regimens in the management of endometriosis-associated pelvic pain. METHODS: Two hundred and one patients were enrolled in this multicenter, randomized, double-blind, 1-year trial. All patients were given an intramuscular injection of leuprolide acetate depot 3.75 mg every 4 weeks. Patients were assigned to one of four treatment groups: Group A received placebos for progestin and estrogen, group B received norethindrone acetate 5 mg daily and placebo for estrogen, group C received norethindrone acetate 5 mg and conjugated equine estrogens 0.625 mg daily, and group D received norethindrone acetate 5 mg and conjugated equine estrogens 1.25 mg daily. Pelvic pain scores were assessed monthly, and bone density was measured after 24 and 52 weeks. RESULTS: By week 8, all four groups showed significant improvement in pelvic pain scores compared with baseline levels. A higher proportion of group D patients terminated the study prematurely due to a lack of improvement in symptoms. Group A experienced a 6.3 +/- 2.3% (P < or = .001) loss in bone density after 52 weeks of treatment, whereas bone density was preserved in all three add-back groups. CONCLUSION: The use of leuprolide acetate depot in combination with norethindrone acetate 5 mg alone, or with norethindrone acetate and conjugated equine estrogens 0.625 mg, provides effective suppression of pelvic pain symptoms associated with endometriosis while protecting against bone loss.