Double-Drug Regimen Using GnRH Analogues

Numerous clinical trials demonstrated that the optimal log-term treatment of pelvic pain caused by endometriosis may involve the use of GnRH ana- logues (GnRH-a) to suppress ovarian estrogen production combined with add- back low doses of estrogen plus progestin or progestin only. Estrogen, as a solitary add back, is less effective and thus is not indicated. Tibolone can be used as add back therapy to prevent hypoestrogenic symptoms. Recently, the post-operative administration of GnRH-a and anastrozole have been suggested to increase the pain-free interval and decrease symptom recurrence rates in patients following surgery for severe endometriosis.