The mifepristone-misoprostol regimen for early medical abortion.

The combination of mifepristone, an antiprogesterone known in the United States as Mifeprex (Danco Laboratories, New York, NY), and misoprostol, a prostaglandin analogue marketed in the United States under the brand name Cytotec (Pharmacia [formerly Searle], Peapack, NJ), provides a nonsurgical abortion in the early stages of a pregnancy. Mifepristone blocks the action of progesterone, a hormone necessary to sustain a pregnancy, whereas misoprostol causes contractions that expel the embryo and other pregnancy tissue. Since September 2000, mifepristone has been approved by the United States Food and Drug Administration for induced abortions of gestations of 49 days or less since the last menstrual period, but is not yet approved for any other uses. Misoprostol has long been approved to prevent and treat stomach ulcers.