[Mifepristone (RU 486): present status, prospectives]

Mifepristone (RU 486) has many therapeutic possibilities, which largely exceed simple interruption of pregnancy. They are due to its unique properties of progesterone--and glucocorticosteroid--receptor blockage. In early interruption of pregnancy, the association with a prostaglandin analogue represents an efficient and well-tolerated method. The safety and comfort of the method have been improved by the association with misoprostol, an oral prostaglandin analogue. Mifepristone can also be used in late pregnancy interruptions for medical reasons, as well as for expulsion of an in utero dead fetus. In these indications, its use allows to decrease or even to avoid the use of prostaglandins, thus diminishing the side-effects due to these products. Several other gynaecological and obstetrical indications seem promising in the future: dilatation and ripening of uterine cervix, induction of labour for medical reasons, contraception. Trials are ongoing to evaluate the antitumoral activity of mifepristone in meningiomas and breast cancer. Finally, its anti-glucocorticosteroid effect is used in the treatment of Cushing's syndromes due to ectopic secretion of ACTH and other indications may be foreseen.