Progesterone receptor modulators and progesterone antagonists in women's health

Both progesterone receptor modulators (PRMs) as well as purl progesterone a ntagonists (PAs) have numerous proven and potential therapeutic application s in female health care. Mifepristone, a PRM with only marginal agonistic a ctivity, together with a prostaglandin can terminate pregnancies of less th an 9 weeks duration; mifepristone is also used in the preparation of women at later gestational stages whose pregnancies are terminated with prostagla ndins or surgery, Mifepristone causes expulsion of the uterine contents fol lowing intrauterine fetal death and promotes dilation of the non-pregnant p rimigravid uterus. It is also effective in the treatment of missed abortion . Together with methotrexate, mifepristone can be used in the medical treat ment of ectopic pregnancy. Both PAs and PRMs display antiproliferative effe cts on the endometrium. Because of this, they have application in the treat ment of endometriosis, an estrogen-dependent condition. They may also be ut ilized to reduce myoma size, acting as both a PA and antiproliferative agen t. Unlike GnRH agonists, long-term use in endometriosis and myoma is not as sociated with loss of bone and hypoestrogenism. PRMs may also be useful in IVF programs to prevent a premature LH surge and to delay the emergence of the implantation window. Some PRMs have potential use as hormone replacemen t therapy in women during menopause or in those with dysfunctional uterine bleeding. (C) 2000 Published by Elsevier Science Inc.