title: Gonadotropin-releasing hormone agonist and add-back therapy: what do the data show?
abstract: OBJECTIVE
  Endometriosis is a gynecologic disorder that can lead to debilitating chronic pelvic pain and infertility. Gonadotropin-releasing hormone agonists (GnRHa) have emerged as a primary medical therapy for patients with symptomatic disease, but secondary hypoestrogenic side effects may limit compliance. Add-back therapy is a means of surmounting this problem.
  
  
  RESULTS
  Progestins such as norethindrone acetate may be administered with or without addition of low doses of estrogens to safely and effectively extend GnRHa therapy while minimizing side effects. Recent studies have demonstrated that the use of add-back enhances compliance and duration of therapy. The initiation of an add-back should not be deferred given evidence demonstrating an increase in vasomotor symptoms and bone loss if not administered concomitantly. The subset of adolescents with endometriosis who require GnRHa therapy should be administered an add-back, but require careful monitoring of bone mineral density.
  
  
  CONCLUSIONS
  Implementation of an appropriately selected add-back will significantly reduce hypoestrogenic side effects, enhance compliance, and allow for prolongation of therapy without interfering with the efficacy of GnRHa in treating symptomatic endometriosis.
authors.affiliation: Colorado Center for Reproductive Medicine, Lone Tree, Colorado, USA. esurrey@colocrm.com
authors.forename: Eric S
authors.initials: ES
authors.lastname: Surrey
mesh_terms: D000293:Adolescent; D000328:Adult; D004715:Endometriosis / Q000188:drug therapy*; D004967:Estrogens / Q000627:therapeutic use; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists*; D020249:Hormone Replacement Therapy / Q000379:methods*; D006801:Humans; D010024:Osteoporosis / Q000139:chemically induced / Q000517:prevention & control; D011372:Progestins / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D004967:Estrogens; D011372:Progestins; D007987:Gonadotropin-Releasing Hormone