Advances in pharmacotherapy for treating endometriosis.

INTRODUCTION: Endometriosis is an estrogen-dependent chronic disease requiring long-term therapy. Therefore, the choice of medical treatment should be based on efficacy, preference of patients, incidence and severity of adverse effects and cost. AREAS COVERED: This review briefly summarizes the currently available medical treatment for endometriosis. The treatments most recently proposed for endometriosis will be described in detail, including gonadotropin-releasing hormone (GnRH) antagonists, aromatase inhibitors (AIs) and the flexible extended combined oral contraceptive. EXPERT OPINION: The oral contraceptive pill and progestogens allow for the treatment of the majority of patients with endometriosis. The flexible extended dosing regimen, containing drospirenone and ethinylestradiol, may be particularly useful in patients suffering severe dysmenorrhea and improving the adherence and compliance with treatment. GnRH agonists may be used in patients resistant to first-line therapy; up to now, limited data are available on the use of GnRH antagonist (such as elagolix) in patients with endometriosis. AIs should be regarded as experimental therapies and used only in patients with symptoms resistant to other therapies; however, the use of these drugs is limited by the possibility to administer the treatment for short-term periods only (6 months) and, similarly to GnRH antagonists, by the high incidence of adverse effects, requiring the use of add-back therapy.