Hormonal contraceptives for the medical treatment of endometriosis
Department of Obstetrics and Gynecology, University of Milano, Milano, Italy
Drugs used in the treatment of endometriosis are not cytoreductive and quiescent implants have been demonstrated in nearly all women treated with danazol, GnRH agonists and progestogens.
Medical therapy is symptomatic and pain release at treatment suspension is the rule.
Hormonal contraceptive preparations are effective in controlling pain symptoms in approximately three out of four women with endometriosis. Their effect does not seem to be inferior to that obtained with other drugs habitually used in treating the disease. Medical treatment plays a role in the overall therapeutic strategy only if it can be administered over a prolonged period of time. Given their good tolerability, minor metabolic effects and low cost, hormonal contraceptives must therefore be considered the drugs of choice.
The effectiveness of hormonal contraceptives is probably partly due to the proven anti-inflammatory effect of progestogens. Most pelvic lesions associated with endometriosis are secondary to the strong inflammatory state caused by the metabolic activity of ectopic endometrium and to the resulting immune response. Furthermore, patients with endometriosis experience heavier menstruations than women without the disease. The reduction of menstrual flow observed with the use of OC or the levonorgestrel IUD can limit pelvic contamination caused by transtubal reflux.
Hormonal contraceptives are currently the only safe and inexpensive alternative to surgery. However, their contraceptive activity limits their use to women who do not wish to have children in the short term.