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Overview: Mifepristone is an oral tablet used to end a pregnancy during the first 10 weeks of pregnancy. Mifepristone works by blocking a hormone needed to maintain a pregnancy. Common side effects include cramping, bleeding, feeling unusually weak or tired, nausea, and diarrhea. Call your healthcare provider right away if you have a prolonged fever, severe pain, or very heavy bleeding.

Uses

What is mifepristone used for?

Mifepristone is commonly used to end a pregnancy during the first 10 weeks of pregnancy. 

Mifepristone may also be used for other conditions as determined by your healthcare provider.

See also: Mifepristone (Korlym)

How does mifepristone work (mechanism of action)?

Mifepristone works by blocking the effects of progesterone, a hormone needed to maintain a pregnancy. This causes changes in the uterus that, when used with another medicine (misoprostol), result in the end of the pregnancy. 

How is mifepristone supplied (dosage forms)?

Brands and other names

  • Mifeprex

Dosage forms and strengths

  • 200 mg oral tablets

How should I store mifepristone?

Mifepristone should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place.

Side Effects

What are the most common side effects of mifepristone?

The most common side effects of mifepristone are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Cramping
  • Bleeding (see below)
  • Nausea or vomiting
  • Feeling unusually weak or tired
  • Fever or chills
  • Headache
  • Diarrhea
  • Dizziness

There may be other side effects of mifepristone that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of mifepristone?

While less common, the most serious side effects of mifepristone are described below, along with what to do if they happen.

Severe Allergic Reactions. Mifepristone may cause allergic reactions, which can be serious. Get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Infection. Some people have had bacterial infections after taking mifepristone, which can lead to a dangerous condition called sepsis. Get help right away if you have any of the following symptoms in the days after taking mifepristone.

  • Fever of 100.4 F (38 C) or higher that lasts longer than four hours
  • Severe pain in your abdomen
  • Tender pelvis
  • Racing heart
  • General ill feeling

Bleeding. It is common to have vaginal bleeding or spotting for a few weeks after taking mifepristone, with heavy bleeding the first few days. While rare, some people may need treatment in a hospital or surgery to stop the bleeding. Get help right away if your bleeding seems very heavy, such as soaking through two thick pads per hour for two hours.

Warnings & Precautions

Who should not use mifepristone?

Allergies to Ingredients. People who are allergic to any of the following should not take mifepristone.

  • Mifepristone
  • Mifeprex
  • Misoprostol
  • Any other medicine known as a prostaglandin
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific mifepristone products they stock.

Ectopic Pregnancy. Mifepristone will not work for an ectopic pregnancy (a pregnancy outside the uterus) and can cause harm. Mifepristone should not be used if you have a confirmed ectopic pregnancy, or a possible one, such as a mass in the tissues near the uterus. 

IUD. People who have an intrauterine device (IUD) should not take mifepristone. Having an IUD may interfere with how well it works. If a healthcare provider removes your IUD, mifepristone can be used.

Adrenal Problems. People with long-term adrenal gland problems should not take mifepristone. It could cause a serious condition called adrenal insufficiency, where the adrenal glands cannot produce enough hormones to help your body manage stress.

Drug Interactions. Mifepristone should not be taken while you are using certain other medicines. Before taking mifepristone, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Bleeding Disorders. People with bleeding problems should not take mifepristone due to a higher risk of heavy bleeding.

Porphyrias. People with inherited nerve or skin problems, called porphyrias, should not take mifepristone. The symptoms of these conditions can be triggered or worsened by mifepristone. 

What should I know about mifepristone before taking it?

Do not take mifepristone unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share mifepristone with other people, even if they have the same condition as you. It may harm them.

Keep mifepristone out of the reach of children.

Mifepristone is only available through a special program from certain healthcare providers and pharmacies. It is important that you follow all program requirements to help ensure safe use of the medicine. For more information, visit www.mifeinfo.com or call 855-MIFEINFO (855-643-3463). 

You must follow up with a healthcare provider within one to two weeks after taking mifepristone. This is important so they can check if the medicine worked safely and effectively. If the medicine did not work as planned, your healthcare provider will discuss options for next steps with you.

Mifepristone does not prevent future pregnancies. To prevent becoming pregnant again, talk to a healthcare provider about when to start or continue using birth control. They can also discuss effective birth control options with you.

What should I tell my healthcare provider before taking mifepristone?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if mifepristone is right for you.

In particular, make sure that you discuss any of the following.

Pregnancy. Mifepristone is commonly used to end a pregnancy during the first 10 weeks (70 days) of pregnancy. Ask your healthcare provider if you have questions about this. 

Breastfeeding. Mifepristone passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should take mifepristone while breastfeeding.

Interactions

Does mifepristone interact with foods or drinks?

Grapefruit can increase the levels of mifepristone in your body, which may raise the risk of side effects. It is best to avoid grapefruit and grapefruit juice before or with mifepristone.

It is unknown if drinking alcohol will affect mifepristone. The risk of nausea, vomiting, or bleeding may be increased if you drink alcohol with mifepristone.

Does mifepristone interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking mifepristone.

  • A corticosteroid, such as dexamethasone, methylprednisolone, or prednisone, which is a medicine for certain inflammatory conditions
  • A blood thinner, which is a medicine used to treat or prevent blood clots

Many other medicines and supplements may alter the blood levels of mifepristone. Tell your healthcare provider about everything you take or have recently taken.

This may not be a complete list of medicines that can interact with mifepristone. Always check with your healthcare provider.

 

 

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much mifepristone?

If you or someone else has taken too much mifepristone, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of mifepristone?

Mifepristone is usually taken as a single dose, followed by another medicine called misoprostol. Follow your healthcare provider’s instructions for when to take each medicine. If you miss a dose, call your healthcare provider right away so they can guide you on next steps.