A drug that blocks the action of progesterone, a hormone that is essential for maintaining a pregnancy. Mifepristone is used to induce abortion up to the 20th week of pregnancy. It is taken by mouth under medical supervision; if the pregnancy is more advanced than 9 weeks gemeprost pessaries may need to be given in addition. Mifepristone is also used for softening and dilating the cervix (neck of the uterus)
before mechanical termination of pregnancy. It is available as tablets on prescription only.
Side effects: include malaise, faintness, headache, nausea, vomiting, rashes, vaginal bleeding (sometimes severe), and (especially after gemeprost) pain in the uterus.
Precautions: mifepristone should not be used if an ectopic pregnancy is suspected or in women with chronic adrenal failure or taking long-term corticosteroids or anticoagulants. It should not be used in combination with gameprost by women over 35 who smoke. Alcohol and smoking must be avoided for two days before gemeprost treatment and on the day of this treatment. Mifepristone should be used with caution by women with asthma, heart, liver or kidney disease, and during breastfeeding. Interactions with other drugs: Aspirin and NSAIDs: should not be taken for at least 8-12 days after mifepristone treatment.
Proprietary preparation: Mifegyne.
