RU 486. The progesterone antagonist
B. D. Weiss
Department of Family and Community Medicine, University of Arizona College of Medicine, Tucson.
The objective of this report is to review the current and potential
therapeutic uses of the progesterone antagonist drug RU 486 (mifepristone).
Publications cited in peer-reviewed journals were identified through a
search of the Index Medicus from 1987 through 1992. A wide range of
research reports was reviewed, including human, animal, and tissue culture
experiments. Data from published reports were included in this report if
they addressed the mechanism of action, clinical indications, and potential
uses for RU 486. The review disclosed that as a progesterone antagonist, RU
486 is clinically effective for inducing first-trimester abortions, for
ripening and dilating the cervix to facilitate intrauterine surgical
procedures, and as a postcoital contragestational agent. As a
glucocorticoid antagonist, RU 486 is useful for treating inoperable cases
of nonpituitary Cushing's syndrome. RU 486 is under investigation for use
as an antineoplastic agent; it has shown promise as a treatment of
meningioma, breast cancer, prostate cancer, and hepatoma. RU 486 may also
have a role in the treatment of endocrinologic conditions such as
endometriosis and premenstrual syndrome. I conclude that RU 486 is
effective and in current clinical use for a number of reproductive
indications and for treatment of Cushing's syndrome. The drug also has
potential as therapy for certain neoplasms and endocrinologic conditions.
