Treatment of endometriosis with a long-acting gonadotropin-releasing hormone agonist.

Sixteen women with endometriosis were treated with daily subcutaneous injections of a potent agonist of gonadotropin-releasing hormone (GnRH) for six months. Ovarian estrogen secretion was reduced to castrate levels during most of the course of treatment. Blinded evaluation of laparoscopic photographs confirmed marked suppression of visually apparent disease, but biopsy specimens showed occult, inactive endometriosis in most cases. Marked pain relief was noted by all patients. As a result of this "medical oophorectomy," the women experienced severe hot flashes, and many had insomnia and emotional disturbances. Vaginal cytology showed menopausal changes but related symptoms were generally mild. Calcium excretion rose to menopausal levels. High-density lipoprotein and total cholesterol remained unchanged. These results indicate that GnRH agonist administration has impressive effects on endometriotic implants, and these actions may be enhanced with longer therapy. Further development of this new form of therapy should involve either use of lesser degrees of ovarian suppression or adjunctive therapy to counter the side effects of "medical oophorectomy."