Safety of medical treatments for endometriosis

All medical treatments for endometriosis are equally effective in relieving pain. However, all of them alleviate pain symptoms for as long as they are used, but pain always relapses when medication is discontinued. Therefore, medications need to be used in the long term.

Formulations of estro-progestins that contain less than 50 µg of estrogen are associated with a low risk of venous thrombosis, myocardial infarction and stroke. When considering the neoplastic effects, data suggest that the overall risk of invasive cancer by age 60 is not increased in previous users of hormonal contraceptives. The use of progestins for contraception has never been associated with an increased risk of breast cancer, venous thromboembolism or bone fractures. Although more data on long-term therapy with progestins are needed, treatment of endometriosis with progestins may be feasible in women with metabolic or cardiovascular contraindications to estroprogestin. The other medications for the treatment of pain associated with endometriosis are less appropriate for long term administration because of side effects (danazol and GnRH analogues), costs (aromatase inhibitors and GnRH agonists) or necessity of complex regimens of associations (GnRH agonists and add back therapy or aromatase inhibitors plus progestins).

Progestins and estroprogestins are safe drugs to use in the long term. Adherence to these medications may be high because, being a contraceptive, they are perceived less as a medication for the treatment of a disease. The annual cost of therapy compares favorably with other available medications. Progestins and estroprogestins represent the first-line medications for the treatment of endometriosis associated pain.