Reviewed on 8/5/2021

What Is Misoprostol and How Does It Work?

Misoprostol is a prescription drug used to reducing the risk of NSAID (nonsteroidal anti-inflammatory drugs, including aspirin)–induced gastric ulcers in patients at high risk of complications from gastric ulcer, such as the elderly and patients with concomitant debilitating disease, as well as patients at high risk of developing gastric ulceration, such as patients with a history of ulcer.

  • Misoprostol has not been shown to reduce the risk of duodenal ulcers in patients taking NSAIDs.
  • Misoprostol should be taken for the duration of NSAID therapy.
  • Misoprostol has been shown to reduce the risk of gastric ulcers in controlled studies of 3 months duration. It had no effect, compared to placebo, on gastrointestinal pain or discomfort associated with NSAID use.

Misoprostol is available under the following different brand names: Cytotec.

What Are the Dosages of Misoprostol?

Dosages of Misoprostol:

Adult and Pediatric Dosage


  • 100 mcg
  • 200 mcg

Dosage Considerations – Should be Given as Follows:

NSAID-Induced Ulcer



  • 200 mcg orally every 6 hours with food; may be decreased to 100 mcg every 6 hours if higher dose is not tolerated; last dose to be administered at bedtime
  • Should take therapy for duration of therapy


  • To avoid possibility of diarrhea, dosing may be initiated at 100 mcg every 6 hours and increased by 100 mcg/day every 3 days until desired dose is achieved

Pregnancy Termination

  • See mifepristone (Mifeprex) drug monograph for FDA approved dosage regimen

Stress Ulcer Prophylaxis (off-label)

  • 100-200 mcg orally every 4-6 hours

Induction of Labor (off-label)

  • 25 mcg (1/4 of 100 mcg oral tablet) intravaginally initially, then repeat at intervals not to exceed every 3-6 hours

Not to be used in patients with previous cesarean delivery or major uterine surgery

Postpartum Hemorrhage (off-label)

  • Prophylaxis: 600 mcg orally within 1 minute of delivery
  • Treatment: 800 mcg orally once; use caution if prophylactic dose already given and adverse effects present or observed
  • Use only in settings where oxytocin not available

Treatment of Incomplete Abortion (off-label)

  • 600 mcg buccally (dissolved in the mouth) once

Fat Absorption in Cystic Fibrosis Patients (off-label)


  • Children under 8 years: safety and efficacy not established
  • Children 8 years and older: 100 mcg orally every 6 hours

Dosage Modifications

Renal impairment

  • Use with caution; peak plasma concentration, half-life, and bioavailability may be increased, but it is not clear whether these increases are of clinical relevance


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What Are Side Effects Associated with Using Misoprostol?

Side effects of misoprostol include:

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Misoprostol?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

Misoprostol has no known severe interactions with other drugs.

Misoprostol has no known serious interactions with other drugs.

Moderate interactions of misoprostol include:

  • croelemer
  • eluxadoline

Misoprostol has no known mild interactions with other drugs.

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns or for more information about this medicine.

What Are Warnings and Precautions for Misoprostol?


  • Bacterial infections reported after use
  • Patients must seek medical attention if excessive bleeding occurs
  • Administration to pregnant women can cause abortion, premature birth, or birth defects
  • Uterine rupture has been reported when drug is administered to pregnant women to induce labor; risk of uterine rupture increases with advancing gestational ages and prior uterine surgery, including cesarean delivery
  • Contraindicated in pregnant women to reduce peptic ulcer risk from nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Warn patients of risk for abortion, and warn them not to give drug to others
  • Use in women of childbearing potential:
    • Do not use for reducing risk of NSAID-induced ulcers in women of childbearing potential unless patient is at high risk for complication from gastric ulcers; may be prescribed in the following situations:
    • Patient has negative serum pregnancy test result within 2 weeks before initiation of therapy
    • Patient is capable of complying with effective contraceptive measures
    • Patient has received both oral and written warnings about misoprostol hazards, risk of possible contraception failure, and danger to other women of childbearing potential should drug be taken by mistake
    • Patient will begin misoprostol only on day 2 or 3 of next normal menstrual period

This medication contains misoprostol. Do not take Cytotec if you are allergic to misoprostol or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


  • Pregnancy when used to reduce risk of NSAID-induced ulcers.
  • Hypersensitivity to misoprostol, prostaglandins, or prostaglandin analogues

Effects of Drug Abuse

  • No information available

Short-Term Effects

  • See "What Are Side Effects Associated with Using Misoprostol?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Misoprostol?"


  • May cause diarrhea; should not be coadministered with other drugs that cause diarrhea (magnesium-containing antacids)
  • Adequate contraception is required in women of childbearing age
  • May cause severe allergic (anaphylactic) reaction
  • May cause chills
  • Unknown whether drug is safe for use in women with severe anemia
  • Misoprostol may cause birth defects, abortion (sometimes incomplete), premature labor or rupture of the uterus if given to pregnant women
  • Safety and efficacy in patients with cardiovascular disease, diabetes, kidney (renal) impairment, or respiratory disease are not established
  • Use with caution in women over 35 years or heavy smokers (these patients were not included in clinical trials)

Off-label use

  • For hospital use only if used off label for cervical ripening, induction of labor, or treatment of serious postpartum hemorrhage
  • Uterine activity and fetal status should be monitored by trained obstetric personnel in hospital setting
  • May be associated with meconium passage, meconium staining of amniotic fluid, and cesarean delivery
  • Maternal shock, maternal death, fetal bradycardia, and fetal death have been reported

Pregnancy and Lactation

  • Do not use misoprostol during pregnancy
  • The risks involved outweigh potential benefits
  • Safer alternatives exist
  • Breastfeeding: misoprostol is rapidly metabolized in mother to misoprostol acid, which is biologically active and is excreted in breast milk; although no published reports of adverse effects of misoprostol in breastfeeding infants exist, caution should be exercised when misoprostol is administered to breastfeeding women


Pancreatitis is inflammation of an organ in the abdomen called the pancreas. See Answer
Medscape. Misoprostol.
RxList. Cytotec.

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