Use of RU-486 as Contraceptive Found Effective
In a finding that could ignite new debate in the United States, Scottish researchers reported today that the so-called French abortion pill RU-486 is a highly effective and safe “morning after” pill to prevent pregnancy.
The pill has yet to be considered for use in the United States because of the highly charged politics of abortion, but its potential as a contraceptive could increase pressure for government approval.
“It is really quite remarkable what they found,” said Dr. David A. Grimes, a USC scientist who has performed research on the drug. “We have defined, for the first time, a true contraceptive role for RU-486. I think it will revolutionize the way RU-486 is viewed in this country.”
Although RU-486 is used in some European countries to induce abortion during the first trimester of pregnancy, the use of the drug reported in today’s New England Journal of Medicine would prevent pregnancy by blocking a fertilized egg from implanting in the uterus if taken within 72 hours of intercourse.
RU-486, the brand name for the drug mifepristone, is manufactured by the French company Roussel-Uclaf and its German parent company, Hoechst. It is used in some European countries, primarily France, as an abortion pill, but it has also been the subject of worldwide research for its possible promise in treating breast cancer, a form of brain cancer called meningioma, endometriosis, glaucoma and a metabolic disorder called Cushing’s syndrome.
Since June, 1989, under pressure from anti-abortion groups, the U.S. Food and Drug Administration has prohibited import of the drug for personal use. Research on RU-486 as an abortion-inducing agent, including Grimes’ work at USC, was halted because of difficulty in obtaining the drug. Only a limited number of studies on RU-486--none on abortion--continue in the United States.
But that may change, said Grimes, who co-authored an editorial accompanying the study in today’s journal.
“This study casts a whole new tone to the ongoing argument and will really help define where people stand,” he said in an interview.
The study included 800 women and adolescents who requested emergency postcoital contraception after having unprotected intercourse within the preceding 72 hours. The women were divided into three age groups and assigned to one of two treatments: a single 600-milligram dose of mifepristone, or the standard therapy of a dose of estrogen followed by a dose of progestogen 12 hours later.
Based on probability, 23 pregnancies should have occurred in each group. But no pregnancies resulted in the mifepristone group and four occurred among the women who received the standard therapy, a difference that is not statistically significant, researcher Anna Glasier of the University of Edinburgh reported in the study.
But the women taking mifepristone tolerated the therapy much better, with fewer reporting nausea (40% compared to 60% taking the standard therapy).
Mifepristone is among a family of drugs called antiprogestins and works to prevent pregnancy by blocking the hormone progesterone, which is necessary for the fertilized egg to implant in the uterus.
“(RU-486) is an antiprogestin, and we know how important progesterone is to implantation,” said Dr. Carol Kurz, a Woodland Hills obstetrician and co-chairwoman of the Los Angeles Coalition for RU-486, an advocacy group. “It makes a lot of sense that it would be effective. And it’s nice to hear it has fewer side effects.”
The major drawback of mifepristone was that it delayed the start of menstruation--ranging from four to 63 days--in 42% of the women, which could be stressful to a woman who worried she was pregnant, Glasier said.
Although side effects might prevent use of the drug as a regular form of contraception, Glasier and Grimes praised mifepristone as a potentially safe and effective emergency contraceptive.
“The real problem with emergency postcoital contraception is not its failure rate or its side effects but the fact that so few women and adolescents who have had unprotected intercourse actually use it,” Glasier said.
In this country, use of postcoital contraception is largely confined to college campus medical clinics and Planned Parenthood centers, Grimes said.
A spokeswoman for anti-abortion groups said many members would be opposed to use of RU-486 as a postcoital contraceptive.
“If something prevents fertilization, we have no quarrel with it,” said Susan Carpenter-McMillan, spokeswoman for the Pro-Family Media Coalition, which represents groups opposed to abortion around the country. But anything that interferes with implantation is in effect aborting a life, she said.
“Once the egg and sperm have united, logically that is where life begins,” Carpenter-McMillan said.
Grimes said medical opinion holds that pregnancy begins at the completion of implantation, 13 to 14 days after conception.
“People who say life begins at the moment of fertilization are biologically naive,” he said.
Hoechst officials have said they will not market RU-486 in the United States in a hostile political climate. But other manufacturers might make their own antiprogestins available, said Marie Bass, coordinator of the Washington-based New Reproductive Health Technologies Project, which supports contraceptive research.
“It’s a whole new family of drugs. The more people know about antiprogestins and the more it is accepted in the international community, our country looks foolish not to be involved in the research,” she said.
