What Is Mifepristone?
Mifepristone is a synthetic steroid compound that acts as a selective progesterone receptor antagonist. Mifepristone blocks the action of progesterone, a hormone necessary for maintaining pregnancy, leading to the detachment of the embryo or fetus from the uterine lining and softening of the cervix. This process is followed by the administration of misoprostol, a prostaglandin analog, which induces contractions and facilitates the expulsion of the pregnancy. It is important to get an ultrasound and know where your pregnancy is in case there is a tubal pregnancy.
Mechanism of Action
- Mifepristone binds to progesterone receptors, blocking the action of progesterone.
- Progesterone is essential for maintaining the uterine lining and supporting pregnancy. Without progesterone, the uterine lining breaks down, and contractions are induced, leading to the expulsion of the fetus.
Indications
- Used for medical abortion up to 10 weeks gestation (70 days from the first day of the last menstrual period).
- Sometimes used in combination with other medications for cervical ripening before surgical abortion procedures.
- Investigational uses include treatment of certain endocrine disorders and cancers.
Side Effects
- Common side effects include nausea, vomiting, abdominal pain, uterine cramping, and vaginal bleeding.
- Serious complications are rare but can include heavy or prolonged bleeding, infection, incomplete abortion, and allergic reactions.
Related Terms
Online References
- Mayo Clinic: Provides an overview of medication abortion, including the medications used, how they work, and what to expect during and after the procedure.
- AAPLOG: Provides a closer look at chemical abortion.
- Lozier Institute: Provides more in-depth information about mifepristone.