RU-486 is often nicknamed "the abortion pill". It's a drug used for medical — as opposed to surgical — abortion; it was initially developed by a French pharmaceutical company, Roussel Uclaf. The drug's generic name is mifepristone and it's marketed under the trade name Mifeprex. It was introduced in France in 1988, and faced a long legal and political battle for licensing in the United States; it received final approval from the Food and Drug Administration in September 2000.
How it works
RU-486 is a synthetic steroid that is very similar to progesterone, a natural hormone that plays a significant role in the menstrual cycle. During pregnancy, progesterone is involved in maintaining the endometrium; elevations in progesterone levels signal pregnancy; the woman's body retains the endometrium instead of menstruating. RU-486, being similar to progesterone, blocks its activity at receptor sites; without the hormonal signal that progesterone creates, the reproductive organs prepare for menstruating. The endometrium is shed, preventing the formation of the placenta. The pregnancy can't be maintained, and the fetus dies.
When used alone, RU-486 is approximately 80% effective; a substantial number of cases require vacuum aspiration afterwards — that is, a surgical abortion — because the fetus or associated tissues are not fully ejected by the uterus. Normally, RU-486 is used in concert with another drug, misoprostol. Misoprostol is a prostaglandin, a class of hormones involved in stimulating dilation of the cervix and initiating uterine contractions. A typical medical abortion involves administration of 600 mg of RU-486 (three pills), followed two days later with 400 μg of misoprostol either by mouth or with vaginal suppositories (unless a complete abortion has already occurred by this point.) The original treatment regimen required the woman to return to the doctor for the misoprostol, but it's becoming more common for women to administer the drug at home. Most women experience a complete abortion within four hours at this point; according to Planned Parenthood, this regimen is 96-97% effective. There is a routine follow-up visit in two weeks to check for any remaining tissue; if necessary, a vacuum aspiration is performed.
Safety
Side effects of medical abortion are similar to those of spontaneous miscarriage: abdominal pain, bleeding, nausea, and diarrhea. Some of the risks of surgical abortion — uterine perforation and the risks inherent in anaesthesia — are eliminated by the use of RU-486. Generally it is quite a safe treatment. It's not safe if there is an ectopic pregnancy (one occurring outside the uterus); it is recommended for use into the seventh week of pregnancy as measured from the first date of the last period (although use into the ninth week is common and generally recognized to be safe). Severe bleeding or infection can occasionally occur, but these risks are present with surgical abortion and natural miscarriage as well. The FDA has recently announced that four women have died in the U.S. as a result of sepsis occurring after the use of RU-486. It is still unknown whether these deaths were caused by RU-486, as sepsis is a risk of both miscarriage and childbirth.
History
Mifepristone was discovered in 1980 by researchers at Roussel Uclaf working on glucocorticoid receptor antagonists; some of the compounds examined blocked the similar progesterone receptor instead. Two years later, clinical testing of the drug began but it appeared not to be as effective as hoped. It was discovered that adding a prostaglandin to the treatment regimen made the treatment far more effective, and France became the first country to approve the drug combination in 1988. However, facing immense pressure, including death threats, from anti-abortion activists, the company announced that in late 1988 that it would not distribute the drug. The French government intervened, and two days later, distribution resumed. The United Kingdom and Sweden were next to approve the drug, in 1991, Germany followed suit in 1992, and by 1999 most European countries had approved it.
All this meant that U.S. anti-abortion groups were girding up for battle. Even though the drug was successful in France and in the process of obtaining approval in the UK and Sweden, the company announced that it had no plans to seek approval in the U.S. or any other country where it anticipated strong political opposition. The first Bush administration convinced the FDA to ban importation of the drug to the U.S. for personal use or research. In 1992, a woman named Leona Benten attempted to circumvent the ban and import it for her own personal use; initially, a court ruled in her favor, but the Supreme Court reinstated the ban.
It wasn't until the Clinton administration that the ban was lifted; one of his first executive actions in January 1993 was to request that the FDA reexamine the ban. The FDA then decided that European clinical trials could be used to demonstrate the drug's safety and expedite U.S. approval. In 1994, Roussel Uclaf donated U.S. patent rights to a New York nonprofit, which conducted clinical trials; in the summer of 1996, an FDA advisory committee recommended approval.
But final approval depended on certain labeling and manufacturing requirements. The nonprofit that had controlled U.S. patents granted manufacturing and distribution rights to the Danco Group, a new pharmaceutical company focused on women's health. They shopped around to find a company to manufacture the drug itself; the first company to agree backed out in 1997, and thus the introduction of RU-486 to the United States was delayed further. Finally, in September 2000, the drug was approved.
References
"The Fight to Make RU-486 Available to U.S. Women: A Chronology in Brief." (http://www.feminist.org/welcome/ru486two.html)
Manufacturer's website (http://www.mifeprex.com/)
Planned Parenthood (http://www.plannedparenthood.org/.../fact-early-abortion-mifepristone.xml)
FDA report, 19 July 2005 (http://www.fda.gov/cder/drug/infopage/mifepristone/default.htm)