[GnRH analogs in gynecology. Possibilities for therapeutic use]

Gonadotropin releasing hormone (GnRH) agonists are synthetic peptide analogues of the natural gonadotropin releasing hormone with a stronger and more prolonged effect than the natural GnRH. Repeated administration of GnRH agonists induces pituitary desensitization followed by a decrease in gonadotropin secretion and estradiol synthesis. Thus reversible hypogonadotropic hypogonadism is produced. Consequently, estrogen-dependent diseases can be treated successfully with GnRH analogues. The therapeutic results obtained in patients with endometriosis, leiomyoma, pubertas praecox, and metastatic breast cancer are discussed. Furthermore the contraceptive properties of GnRH analogues, and combination treatment with HMG to induce ovulation is reviewed.