Gonadotrophin-releasing hormone agonists for endometriosis

Gonadotrophin-releasing hormone (GnRH) agonists include the goserelin implant and the nafarelin intranasal spray. Use of GnRH agonists for endometriosis requires specialist advice. They may be used after surgery, especially if endometriotic lesions were not completely excised, or when other treatments have failed.

Contraception must be used concurrently during treatment with GnRH agonists.

GnRH agonists may cause hypoestrogenic adverse effects (eg hot flushes, vaginal dryness, decreased bone mineral density), which limit their duration of use to 6 months. Estrogen and progestogen replacement (with doses typically used for combined menopausal hormone therapy) reduce these adverse effects, allowing GnRH agonist use for up to 2 years. Use GnRH agonists with caution in young people, particularly adolescents, because GnRH agonists may limit peak bone mass.

Suitable regimens for GnRH agonists for endometriosis include:

Intranasal decongestants should not be used for at least 30 minutes after nafarelin as they may reduce its absorption.