MIFEPRISTONE (RU486) - A REVIEW

Objective: To review the literature concerning the mechanism of action and pharmacodynamics of mifepristone (RU486), potential new uses of R U486, and its current use not only as an abortifacient but also as the rapy for endometriosis, leiomyoma, breast cancer, and meningioma. Data Identification and Selection: Studies that relate to RU486 were ident ified through a MEDLINE search. Conclusion(s): RU486 is an 11 beta-dim ethyl-amino-phenyl derivative of norethindrone with a high affinity fo r P and glucocorticoid receptors. The receptor binding is not followed by transcription of P-dependent genes. Mifepristone effectively block s P receptors in the placenta, resulting in the termination of pregnan cy. In addition, it has been used in the treatment of leiomyomata, end ometriosis, advanced breast cancer, and meningioma. It is a powerful t ool to study the molecular action of P and in the future may be used a s an estrogen-free contraceptive. (C) 1997 by American Society for Rep roductive Medicine.