Low-dose mifepristone matches GnRH agonists for uterine fibroids.(Six Small Trials)

SCOTTSDALE, ARIZ. -- Low-dose mifepristone taken daily by women with uterine fibroids can significantly reduce fibroid size and symptoms, limited data suggest.

The oral antiprogestin was as effective as injections of GnRH agonists, the most common medical therapy for uterine fibroids, in a total of 166 patients in six small trials, Dr. Alison F. Jacoby said at an international congress on uterine fibroids sponsored by the American Association of Gynecologic Laparoscopists.

Patients must limit GnRH agonist therapy to 6 months to avoid significant bone loss from the treatment.

Mifepristone, on the other hand, is a selective progesterone receptor modulator, a new class of drugs that may make long-term medical management of fibroids possible for the first time if upcoming studies support their use, said Dr. Jacoby of the University of California, San Francisco.

Mifepristone, marketed as Mifeprex and sold in 200-mg tablets, is indicated solely for the medical termination of an intrauterine pregnancy through 49 days' pregnancy.

In the current study, a search of the medical literature from 1985 to 2002 in three large computerized databases plus a review of abstracts from U.S. and European ob.gyn. meetings in those years, yielded four studies in English and two in Chinese on mifepristone for the treatment of uterine fibroids.

Two studies were randomized, controlled comparisons between mifepristone and a GnRH agonist and four were nonrandomized, prospective studies on mifepristone use, Dr. Jacoby said.