Maintenance therapy with dienogest following gonadotropin-releasing hormone agonist treatment for endometriosis-associated pelvic pain

Objective: To examine whether long-term administration of dienogest following gonadotropin-releasing hormone agonist (GnRH-a) therapy would prolong the relief of pelvic pain while reducing the amount of irregular uterine bleeding. Study design: This was a prospective, non-randomized clinical trial. Among the patients suffering from chronic pelvic pain associated with recurrent endometriosis, Group G (n = 38) received GnRH-a for 46 months and then dienogest (1 mg/day) for 12 months. The dose of dienogest was increased to 1.5 or 2 mg/day when a patient had uncontrollable uterine bleeding {n = 15(39%)}. Group D (n = 33) received only dienogest (2 mg/day) for 12 months. Pelvic pain was assessed using a visual analog scale (VAS). Uterine bleeding was semi-quantified using a pictorial blood loss assessment chart (PBAC). Results: In Group G, GnRH-a significantly reduced the VAS score for pelvic pain, and alleviation was maintained during the 12-month therapy with dienogest. There was no significant difference in pain reduction between Group G and Group D. The PBAC score during the first 6 months on dienogest was significantly smaller in Group G than in Group D. Conclusion: Treatment with a GnRH-a followed by long-term dienogest therapy maintains the relief of endometriosis-associated pelvic pain achieved with GnRH-a therapy for at least 12 months. This regimen reduces the amount of irregular uterine bleeding that often occurs during the early phase of dienogest therapy. (C) 2011 Elsevier Ireland Ltd. All rights reserved.