mifepristone /mif′əpris″tōn/ , an antiprogestin used with misoprostol or other prostaglandins that induces abortion if taken within the first 7 weeks of pregnancy. Two days after taking the drug to end the pregnancy, the woman must take a second drug to cause strong uterine contractions that expel the fetus. Mifepristone is reportedly effective 95.5% of the time, and serious complications are rare. However, the procedure may be somewhat painful, and a small percentage of patients have required blood transfusions. If the drug regimen fails to terminate the pregnancy, the woman must arrange for a surgical abortion to complete the process. Also called abortion pill, RU-486.
