Drug-based abortion methods typically require that a woman take two types of drugs within the first weeks of a confirmed pregnancy. In one method, a pregnant woman first takes the drug mifepristone, also known as RU-486, which blocks progesterone, a hormone needed to maintain the pregnancy.
About 48 hours later, she takes another drug called misoprostol. Misoprostol is a prostaglandin (a hormone-like chemical produced by the body) that causes contractions of the uterus, the organ in which the fetus develops. These uterine contractions expel the fetus.
Another type of drug combination that induces abortion is the use of misoprostol with methotrexate, an anticancer drug that interferes with cell division. A physician first injects a pregnant woman with methotrexate. About a week later, the woman takes a pill containing misoprostol to induce uterine contractions and expel the fetus.
These drug-based abortion methods effectively end pregnancy in 95 percent of the women who take them. The use of drugs to induce abortion has not been widely adopted by women in the United States for a number of reasons. These drugs can cause unpleasant side effects-some women experience nausea, cramping, and bleeding. More serious complications, such as arrhythmia, edema, and pneumonia, affect the heart and lungs and may cause death. Perhaps the primary deterrent is that these drug-based abortion methods require at least three visits to a physician over a period of several days, and these methods are no cheaper than a surgical abortion.