Add-back therapy and gonadotropin-releasing hormone agonists in the treatment of patients with endometriosis: can a consensus be reached? Add-Back Consensus Working Group.

OBJECTIVE

To reach a consensus on the role of add-back therapy for patients with endometriosis administered GnRH agonists (GnRH-a).

DESIGN

Results of consensus conference reviewing MEDLINE search of English language abstracts of both prospective and retrospective series.

SETTING

Consensus conference of 31 specialists in gynecologic surgery and reproductive endocrinology.

PATIENT(S): Patients with symptomatic endometriosis who were candidates for GnRH-a therapy in treatment courses ranging in duration from 6 to 12 months.

INTERVENTION(S): Oral steroidal and nonsteroidal add-back regimens.

MAIN OUTCOME MEASURE(S): Alteration in painful symptoms, extent of disease, vasomotor symptoms, bone mineral density, and serum lipid profile.

RESULT(S): When added to GnRH-a for 6 months, both 2.5 mg of norethindrone and 0.625 mg of conjugated equine estrogens with 5 mg/d of medroxyprogesterone acetate provide effective relief of vasomotor symptoms and decrease but do not eliminate bone mineral density loss. During 12 months of GnRH-a therapy, bone mineral density loss is eliminated effectively with an add-back of 5 mg of norethindrone acetate alone or in conjunction with low-dose conjugated equine estrogens. Organic bisphosphonates also may play a role.

CONCLUSION(S): In patients with symptomatic endometriosis, the efficacy of GnRH agonists may be preserved and therapy prolonged while overcoming hypoestrogenic side effects with the use of appropriate add-back regimens.