mifepristone

Mifepristone 

Definition

Mifepristone is a pill that can be taken as an alternative to a surgical abortion.

Purpose

This medication most often is used for ending early pregnancies. In 2003, studies were surfacing reporting other possible uses for mifepristone, at least at low doses. These studies included its possible use in treating psychotic depression. Low-dose mifepristone also showed success as a treatment for uterine fibroids, or benign growths in the muscular tissue of a woman's uterus. However, many uses of the drug other than for abortions were still experimental, even if promising.

Mifespristone's primary use for medical abortions is preferred by many over surgical approaches to abortions. It has emerged as a form of emergency contraception when taken at low does within a short time period following possible conception.

Precautions

Women who are more than seven weeks pregnant (or 49 days since their last menstrual period) should not take mifepristone. Other reasons to avoid mifepristone include: use of an intrauterine device (IUD), ectopic pregnancy, use of blood thinners, bleeding disorders, use of steroid medications, allergies to mifepristone or similar drugs and lack of access to medical help within two weeks after the treatment. When the drug is used at low doses as emergency contraception, it poses few side effects.

Description

Mifepristone, sold commercially under the name Mifeprex, also is known as RU-486, the abortion pill, the early option pill for medical abortion. While it has been used for many years in Europe, mifepristone has only been available for use in the United States since the U.S. Food and Drug Administration (FDA) approved it in 2000 for use in abortion. More than 37,000 abortions were performed using the pill in the first six months of 2001.

This drug causes pregnancy to end by blocking the female hormone progesterone. The lack of progesterone makes the uterus shed its lining, which causes bleeding similar to a menstrual period. Three days after taking mifepristone, women are given a second drug, misprostol, to cause uterine contractions that expel the contents of the uterus. Most women are able remain in their own home while they pass the fetus.

Preparation

Before taking mifepristone, health care providers likely will give the woman a urine or blood test to be sure that she is, in fact, pregnant. They also may give her some counseling and support. Once she has made the decision to use mifepristone, they will ask her to sign a written statement that she has decided to end her pregnancy.

Aftercare

Using mifepristone and misoprostol causes heavy bleeding and cramping. Doctors can offer pain medicine, such as Motrin, to ease the cramps. For two weeks after treatment with mifepristone, health care providers likely will ask patients to abstain from sexual intercourse, heavy lifting and strenuous exercise. They also may advise against breast-feeding, since scientists are not sure if the drug is present in breast milk.

Physicians require patients to come in for a follow-up visit 14 days after their first dose of mifepristone to verify that they are no longer pregnant and that they are properly healing.

Risks

Other common side effects include: fatigue, headaches, dizziness, nausea, vomiting, diarrhea and low-back pain.

Since pregnancy hormones are in flux after a medical abortion, many women have emotional side-effects, such as mood swings, depression or a mild case of the blues. These feelings usually subside when hormones stabilize a few weeks later. For those who feel stuck in their grief or anger about the situation, counseling or support groups may offer relief.

Normal results

Most women feel better after about two weeks. Bleeding and spotting usually occurs for 9-16 days, but may last for a month.

Abnormal results

In some cases, mifepristone does not completely end the pregnancy. If the fetus is still left inside the uterus, a doctor may recommend a surgical abortion, or a procedure called dilation and curettage (D and C). About five to eight of every 100 women who take mifepristone go on to have a surgical abortion, according to the FDA. During a D and C, which usually is done at a hospital or clinic under a local anesthetic, a physician dilates the cervix, then uses an instrument to scrape any residual tissue away from the walls of the uterus. This allows the heavy bleeding to eventually stop so a woman can return to her normal cycle sooner.

Key terms

Dilation and curettage (D and C) — During this surgical procedure, a physician dilates the cervix, then uses an instrument to scrape tissue away from the walls of the uterus.

Misprostol — A drug used in combination with mifepristone to cause uterine contractions that expel the contents of the uterus.

Resources

Periodicals

"Abortion Pills Account For 5% of U.S. Abortions." Medical Letter on the CDC and FDA February 9, 2003: 7.

"The Abortion Pill's Grim Progress." Mother Jones 24 (January 1, 1999).

Grimes, David A, Mitchell D. Creinin. "Induced Abortion: an Overview for Internists." Annals of Internal Medicine April 20, 2004: 620-627.

"Low-dose Mifepristone Blocks Pregnancy by Altering Ovarian Function." Drug Week March 5, 2004: 107.

"Treatments for Depression with Psychosis." Harvard Mental Health Letter August 2003.

Walling, Anne D. "Low-dose Mifepristone Shrinks Uterine Fibroids." American Family Physician September 1, 2003: 956.

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mifepristone /mif·e·pris·tone/ (mif?e-pris´ton) RU-486; an antiprogestin used with misoprostol or other prostaglandin to terminate pregnancy in the first trimester.

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mi·fep·ri·stone (m-fpr-stn)

n.

See RU 486.

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mifepristone

a compound with antiprogesterone and antiglucocorticoid activity. Used as an abortifacient and in the management of hyperadrenocorticism.

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mifepristone (RU-486) Warning - Hazardous drug!

Mifegyne (UK), Mifeprex

Pharmacologic class: Synthetic steroid

Therapeutic class: Antiprogestational agent, abortifacient

Pregnancy risk category NR

FDA Boxed Warning

• Rare cases of serious and sometimes fatal infections and bleeding have followed spontaneous, surgical, and medical abortions, including after mifepristone use. Before starting drug, inform patient of risk of these serious events and discuss medication guide and patient agreement. Ensure that patient knows whom to call and what to do, including going to emergency department (ED) if none of provided contacts are reachable; if she experiences sustained fever, severe abdominal pain, prolonged heavy bleeding, or syncope; or if she has abdominal pain or discomfort or general malaise (including weakness, nausea, vomiting, or diarrhea) more than 24 hours after taking drug.
• Patients with serious bacterial infections and sepsis may present without fever, bacteremia, or significant pelvic examination findings after abortion. Rare deaths have occurred in patients without fever, with or without abdominal pain, but with leukocytosis with marked left shift, tachycardia, hemoconcentration, and general malaise. Maintain high index of suspicion to rule out serious infection and sepsis.
• Advise patient to take medication guide with her if she visits ED or another healthcare provider who didn't prescribe drug, so provider will be aware that patient is undergoing medical abortion.

Action

Antagonizes progesterone receptor sites, inhibiting activity of endogenous and exogenous progesterone and stimulating uterine contractions, which causes fetus to separate from placental wall

Availability

Tablets: 200 mg

⊘Indications and dosages

➣ Termination of intrauterine pregnancy through day 49 of pregnancy

Adults: On day 1, mifepristone 600 mg P.O. as a single dose. On day 3, misoprostol 400 mcg P.O. (unless abortion has been confirmed).

Contraindications

• Hypersensitivity to drug, misoprostol, or other prostaglandins
• Confirmed or suspected ectopic pregnancy or adnexal mass
• Chronic adrenal failure
• Bleeding disorders
• Concurrent anticoagulant therapy or long-term corticosteroid therapy
• Presence of intrauterine device (IUD)
• Inherited porphyrias

Precautions

Use cautiously in:
• cardiovascular, respiratory, renal, or hepatic disorders; hypertension; type 1 diabetes mellitus; anemia; jaundice; seizure disorder; cervicitis; infected endocervical lesions; acute vaginitis; uterine scarring.

Administration

• Before giving, make sure patient doesn't have an IUD in place.
• Give only in health care facility under supervision of health care provider qualified to assess pregnancy stage and rule out ectopic pregnancy.
• Administer with fluids, but not with grapefruit juice.
• Confirm pregnancy termination 14 days after initial dose.

Route	Onset	Peak	Duration
P.O.	Rapid	90 min	11 days

Adverse reactions

CNS: dizziness, fainting, headache, weakness, fatigue, insomnia, asthenia, anxiety, syncope, rigors

EENT: sinusitis

GI: nausea, vomiting, diarrhea, abdominal cramping, dyspepsia

GU: vaginitis, leukorrhea, uterine cramping, pelvic pain, uterine hemorrhage

Hematologic: anemia

Musculoskeletal: leg pain, back pain

Skin: fever

Other: viral infections

Interactions

Drug-drug. Carbamazepine, dexamethasone, phenobarbital, phenytoin, rifampin: decreased mifepristone blood level and effects

Drugs metabolized by CYP450-3A4: decreased mifepristone metabolism and increased effects

Erythromycin, itraconazole, ketoconazole: inhibited mifepristone metabolism and increased blood level

Drug-diagnostic tests. Hematocrit, hemoglobin: decreased values

Red blood cells: decreased count

Drug-food. Grapefruit juice: decreased mifepristone blood level and effects

Patient monitoring

• Assess vital signs, breath sounds, and bowel sounds.
• Monitor uterine contractions and type and amount of vaginal bleeding.
• Evaluate CBC.

Patient teaching

• After administration, tell patient she'll need to return in 48 hours for a prostaglandin drug or to verify pregnancy termination.
• Tell patient she'll have contractions for 3 or more hours after receiving drug and that vaginal bleeding may last 9 to 16 days.
☞ Instruct patient to contact prescriber if she has persistent or extremely heavy vaginal bleeding, extreme fatigue, or orthostatic hypotension.
• Caution patient that vaginal bleeding does not prove that complete abortion has occurred. Tell her she'll need follow-up appointment 2 weeks later to verify pregnancy termination.
• Inform patient that she's at risk for pregnancy right after abortion is complete. Encourage appropriate contraceptive decision.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.