Mifeprex

Pronunciation: MIFF-eh-prex
Generic name: mifepristone
Dosage form: oral tablet
Drug classes: Progesterone receptor modulators, Uterotonic agents

Medically reviewed by Carmen Pope, BPharm. Last updated on May 22, 2024.

What is Mifeprex?

Mifeprex is an oral progestin antagonist that may be given in combination with misoprostol to end an early pregnancy when it has been 70 days or less since the first day of a patient’s last menstrual period (10 weeks or less).

• Using a combination of Mifeprex and misoprostol in this way is termed a medical abortion.
• Mifeprex is not approved for ending pregnancies that are further along (more than 10 weeks).
• FDA regulations allow certified healthcare professionals and pharmacies to dispense Mifeprex and misoprostol for medical abortion both in healthcare facilities and by telehealth and mail.

Mifeprex selectively blocks progesterone via the progesterone receptor at low doses and when used to terminate a pregnancy, Mifeprex works by competing with progesterone at progesterone-receptor sites. This blocks the activity of naturally occurring progesterone, resulting in effects on the uterus and cervix that, when combined with misoprostol, result in the termination of an intrauterine pregnancy by sensitizing the lining of the uterus to the contraction-inducing activity of prostaglandins.

Mifeprex was first FDA-approved on September 28, 2000.

Mifeprex side effects

Mifeprex may cause serious side effects, such as serious infection, heavy bleeding, and abdominal pain (see warnings below)

Cramping and vaginal bleeding are expected with this treatment. Usually, these symptoms mean that the treatment is working. But sometimes you can get cramping and bleeding and still be pregnant. This is why you must follow up with your healthcare provider approximately 7 to 14 days after taking Mifeprex and misoprostol.

• If you are not already bleeding after taking Mifeprex, you probably will begin to bleed once you take misoprostol, the medicine you take 24 to 48 hours after Mifeprex.
• Bleeding or spotting can be expected for an average of 9 to 16 days and may last for up to 30 days.
• Your bleeding may be similar to, or greater than, a normal heavy period. You may see blood clots and tissue. This is an expected part of passing the pregnancy.

The most common side effects reported of Mifeprex affecting 15% or more women are nausea, weakness, fever/chills, vomiting, headache, diarrhea, and dizziness.

These are not all the possible side effects of Mifeprex. Call your healthcare provider for medical advice about any side effects that bother you or do not go away. You may report side effects to the FDA at 1-800-FDA-1088.

Related/similar drugs

oxytocin, mifepristone, Pitocin, Hemabate, carboprost, dinoprostone topical

Warnings

Serious side effects reported in females taking Mifeprex and misoprostol to terminate a pregnancy include:

Serious infection that has resulted in death has occurred in a very small number of cases although it is not clear if Mifeprex and misoprostol were the cause. Contact your healthcare provider right away if you have any of the following:

• Heavy bleeding, especially if you bleed enough to soak through two thick full-size sanitary pads per hour for two consecutive hours or if you are concerned about heavy bleeding. In about 1 out of 100 women, bleeding can be so heavy that it requires a surgical procedure (surgical aspiration or D&C).
• Abdominal pain, abdominal discomfort, or “feeling sick”, including weakness, nausea, vomiting, or diarrhea, with or without fever, more than 24 hours after taking Mifeprex. These symptoms may be a sign of a serious infection or another problem (including an ectopic pregnancy, a pregnancy outside the womb)
• A high fever (100.4°F or higher) that lasts for more than 4 hours. Fever may be a symptom of a serious infection or another problem.

If you cannot reach your healthcare provider for any of these problems, go to the nearest hospital emergency room. Take your Mifeprex Medication Guide with you or tell them that you have recently taken medicine to terminate a pregnancy.

Rhesus immunization. Using Mifeprex requires the same preventive measures as those taken before and during surgical abortion to prevent rhesus immunization.

Before taking Mifeprex

Do not take Mifeprex to terminate a pregnancy if you:

• have a pregnancy that is more than 70 days (10 weeks). Your healthcare provider may do a clinical examination, an ultrasound examination, or other testing to determine how far along you are in pregnancy
• are using an IUD (intrauterine device or system). It must be taken out before you take Mifeprex
• have been told by your healthcare provider that you have a pregnancy outside the uterus (also called an ectopic pregnancy)
• are allergic to Mifeprex, mifepristone, misoprostol, Korlym, Cytotec, or Arthrotec
• have problems with your adrenal glands (chronic adrenal failure).
• take a medicine to thin your blood, such as dabigatran or warfarin
• have a bleeding problem
• have porphyria
• take certain steroid medicines.

Tell your healthcare provider if you:

• cannot follow up within approximately 7 to 14 days of your first visit
• are breastfeeding
• are taking medicines, including prescription and over-the-counter medicines, vitamins, and herbal supplements (see interactions below).

Ask your healthcare provider if you are not sure about all your medical conditions before taking Mifeprex.

Breastfeeding

Mifeprex can pass into your breast milk. The effect of Mifeprex on the breastfed infant or milk production is unknown.

How should I take Mifeprex?

Take Mifeprex exactly as your doctor tells you.

The usual dosage for a medical abortion is 200 mg of Mifeprex on Day 1, followed 24 to 48 hours later by 800 mcg misoprostol taken buccally (see below).

• The Mifeprex tablet is swallowed whole.
• The misoprostol tablets are taken buccally. You put them between your top lip and gum (in your cheek pouch).
  • Place 2 misoprostol tablets in each cheek pouch for 30 minutes and then swallow anything left over with a drink of water or another liquid.
• The medicines may not work as well if you take misoprostol sooner than 24 hours after Mifeprex or later than 48 hours after Mifeprex.

Misoprostol often causes cramps, nausea, diarrhea, and other symptoms. Your healthcare provider may send you home with medicines for these symptoms.

• The pregnancy is likely to be passed from your uterus within 2 to 24 hours after taking the misoprostol tablets.
• When the pregnancy is passed from the uterus, you will have bleeding and cramping that will likely be heavier than your usual period.
• About 2 to 7 out of 100 women taking Mifeprex and misoprostol will need a surgical procedure because the pregnancy did not completely pass from the uterus or stop bleeding.
• Follow your healthcare provider's advice about what to do if you have severe side effects (see warnings above).

You will need to talk to a healthcare provider in 7 to 14 days for a follow-up assessment to confirm that the pregnancy has been terminated.

• Prolonged heavy vaginal bleeding is not proof of a complete abortion.
• If the treatment fails and the pregnancy continues, the risk of fetal malformation is unknown.
• It is recommended that ongoing pregnancy be managed by surgical termination.

What should I avoid while taking Mifeprex?

Do not drink grapefruit juice while you take Mifeprex. Grapefruit juice may increase the amount of Mifeprex in your blood and increase your risk of side effects.

What happens if I am still pregnant after taking Mifeprex with misoprostol?

If you are still pregnant, your healthcare provider will talk with you about a surgical procedure to end your pregnancy. In many cases, this surgical procedure can be done in the office/clinic. The chance of birth defects if the pregnancy is not ended is unknown.

Will I be able to get pregnant again after having a medical abortion?

There is no research to suggest that taking Mifeprex and misoprostol for a medical abortion will affect your future fertility and the ability to become pregnant, although animal studies have shown there may be some disruption to your menstrual cycle for up to 3 weeks after taking the combination.

Another pregnancy can occur following a medical abortion before your periods resume.

You can start using contraception as soon as the pregnancy expulsion has been confirmed, or before you resume sexual intercourse.

What other medications will affect Mifeprex?

Tell your doctor about all of the medicines you take, including prescription and nonprescription medicines, vitamins, and herbal supplements.

CYP3A4 inhibitors or inducers may affect Mifeprex taken as part of a medical abortion regimen, with inhibitors increasing Mifeprex concentrations and inducers lowering them. Use with caution.

Ask your doctor or pharmacist for a list of these medicines if you are not sure. Know the medicines you take. Keep a list of them to show to your doctor and pharmacist. See the prescribing information for a full list of interactions.

Storage

Store Mifeprex at room temperature, between 68°F to 77°F (20°C to 25°C).

Keep out of reach of children.

Mifeprex ingredients

Active ingredient: mifepristone 200mg

Inactive ingredients: colloidal silica anhydrous, corn starch, povidone, microcrystalline cellulose, and magnesium stearate.

Available as 200 mg tablets.

Manufacturer

Danco Laboratories, LLC.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer