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Abortion is an issue that has polarized the U.S. Many Americans believe a woman has the right to have an abortion if she chooses, while another large sector of the population believes that abortion is murder and should therefore be illegal.

For decades, the two sides have been engaged in a bitterly fought battle over the legality of this medical procedure. As a consequence of this unrest, companies have been cautious about developing and introducing new birth control and abortion-related drugs for fear of boycotts of all company products.

RU-486 is one such drug that was delayed from entering the U.S. market for years because of the turbulence related to abortion. The drug, which was approved for use in France under the trade name Mifepristone in 1988, was not available to women in the U.S. until 2000.

Known as the "abortion pill," RU-486 takes part of its name from Roussel-Uclaf--the French pharmaceutical company where it was first synthesized in 1980--and the other part from an arbitrary lab serial number. It is a synthetic steroid that competes with progesterone for receptors. (Progesterone is a steroid hormone that is key to maintaining pregnancy.) RU-486 is available in the U.S. from qualified health care providers and is only approved for terminating pregnancy up to the seventh week.

The research that led to RU-486, however, was not intended to yield an abortion drug. Instead, researchers were studying the glucocorticoid antagonist ability of the drug. In screening the drug, researchers found that it had both antiglucocorticoid activity as well as a high affinity for progesterone receptors.

It is this latter finding that steroid hormone authority and company consultant Etienne-Emile Baulieu encouraged Roussel-Uclaf to focus on. Unfortunately, the power of RU-486 in fertility control has hampered studies of its use as an antiglucocorticoid drug in the treatment of certain types of breast cancers, glaucoma, and Cushing's syndrome--a condition caused by excess glucocorticoids.

The drug originally entered the French marketplace in September 1988, but sales were almost immediately suspended by Roussel-Uclaf when antiabortion groups threatened to boycott the company. The French Ministry of Health quickly stepped in that same year and ordered Roussel-Uclaf to return the drug to the market. By the end of 1988, Roussel-Uclaf had suspended RU-486 sales in markets outside France, such as China, the U.K., Sweden, and the Netherlands.

It's not surprising that after this experience Roussel-Uclaf did not want to get entangled in the abortion controversy in the U.S. and opted not to make RU-486 available here. After several years and mounting pressure, however, the company decided in 1994 to donate the U.S. rights to the New York City-based Population Council, a nonprofit reproductive health and population control research institution. The Population Council conducted clinical trials and licensed RU-486 to Danco Laboratories, which markets it as Mifeprex.

Danco Laboratories to date has supplied approximately 400,000 Mifeprex doses to health care providers. The drug is administered in the doctor's office and requires two follow-up visits: one 48 hours after the initial administration of Mifeprex for ingestion of tablets of misoprostol, a prostaglandin that causes uterine contractions to help expel the embryo, and another visit two weeks later to ensure that the abortion is complete. This regimen of Mifeprex and misoprostol is more than 90% effective. Side effects of Mifeprex include vaginal bleeding and cramping, which can require medical assistance.

Supporters of RU-486 say that this process gives a woman a more private alternative to surgical abortions. Its use also provides a safer option for women in developing countries, where surgical abortions are often performed in unsanitary conditions and pose serious health risks.

Opponents question the safety of RU-486. They also worry that the option of taking a few pills to end a pregnancy will make abortions more generally accessible because women will no longer have to travel to clinics with surgical abortion capabilities.

The future use of RU-486 remains intertwined with the abortion battle and thus is a prime target for antiabortion advocates. But as long as abortion remains legal, doctors will continue to offer Mifeprex as a safe option for early-term pregnancy termination.—SUSAN MORRISSEY


The Top Pharmaceuticals
That Changed The World
Vol. 83, Issue 25 (6/20/05)
Table Of Contents


RU-486 structure


  • (11,17)-11-[4-

CAS Registry

  • 84371-65-3

Other Names

  • RU-486
  • Mifeprex


1988, Roussel-Uclaf, in France


  • About 400,000 doses administered in U.S. since approval in 2000