title: Extending the treatment boundaries: Zoladex and add-back.
abstract: OBJECTIVE
  To review the evidence that add-back hormone replacement therapy (HRT) can ameliorate the metabolic consequences of gonadotropin-releasing hormone (GnRH) agonist treatment in women with symptomatic endometriosis.
  
  
  METHODS
  A review of relevant literature.
  
  
  RESULTS
  Early studies suggested that add-back HRT maintained bone mineral density (BMD) without reducing the symptomatic benefit of GnRH treatment. Both high-dose progestogen and low dose progestogen plus cyclical etidronate are effective in maintaining BMD. Standard and low dose HRT add-back may be more effective in relieving the hypo-estrogenic side-effects of GnRH agonist therapy. Randomized controlled studies have shown that both low-dose and standard-dose add-back HRT reduce the side-effects of GnRH agonist therapy, and that this benefit extends to 12 months of treatment.
  
  
  CONCLUSIONS
  GnRH agonist treatment with add-back HRT seems to offer the hope of improved treatment for women with endometriosis, but the optimum treatment duration and time to start HRT have yet to be defined.
authors: Department of Obstetrics and Gynecology, University of Colorado, Denver, USA.
authors: W D
authors: WD
authors: Schlaff
mesh_terms: D015519:Bone Density; D004715:Endometriosis / Q000188:drug therapy*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists; D017273:Goserelin / Q000627:therapeutic use*; D020249:Hormone Replacement Therapy; D006801:Humans
chemical_list: D017273:Goserelin; D007987:Gonadotropin-Releasing Hormone