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Naloxegol Side Effects

Medically reviewed by Last updated on Feb 12, 2021.

In Summary

Commonly reported side effects of naloxegol include: abdominal pain. Other side effects include: diarrhea and flatulence. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to naloxegol: oral tablet

Side effects requiring immediate medical attention

Along with its needed effects, naloxegol may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking naloxegol:

Less common

  • Anxiety
  • chills
  • diarrhea
  • increased sweating
  • irritability
  • stomach pain
  • yawning

Incidence not known

  • Bloody, black or tarry stools
  • heartburn
  • indigestion
  • nausea
  • severe abdominal or stomach pain, cramping, or burning
  • trouble breathing
  • vomiting of material that looks like coffee grounds, severe and continuous

Side effects not requiring immediate medical attention

Some side effects of naloxegol may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Bloated
  • excess air or gas in the stomach or bowels
  • full feeling
  • passing of gas

Less common

For Healthcare Professionals

Applies to naloxegol: oral tablet


The most common adverse reactions include abdominal pain, nausea, diarrhea, headache, vomiting, and flatulence.[Ref]


Common (1% to 10%): Possible opioid withdrawal (3 or more symptoms on the same day including, but not limited to hyperhidrosis, chills, diarrhea, abdominal pain, anxiety, irritability, and yawning)[Ref]

Possible opioid withdrawal defined as at least 3 adverse reactions potentially related to opioid withdrawal occurring on the same day and not all related to the gastrointestinal system occurred in less than 1% of patients (5 of 441) receiving the 12.5 mg dose and 3% of patients (14 of 446) receiving the 25 mg dose. Symptoms included, but were not limited to hyperhidrosis, chills, diarrhea, abdominal pain, anxiety, irritability, and yawning. For patients receiving methadone, higher frequencies of gastrointestinal adverse reactions were observed compared with other opioids.[Ref]


Very common (10% or more): Abdominal pain (up to 21%)

Common (1% to 10%): Diarrhea, nausea, flatulence, vomiting[Ref]

Reports of severe abdominal pain and/or diarrhea resulting in hospitalization have occurred. Most cases were reported at the higher dose and within a few days of initiating therapy.[Ref]


Common (1% to 10%): Hyperhidrosis[Ref]

Nervous system

Common (1% to 10%): Headache[Ref]


Common (1% to 10%): Nasopharyngitis[Ref]


1. "Product Information. Movantik (naloxegol)." Astra-Zeneca Pharmaceuticals, Wilmington, DE.

2. Cerner Multum, Inc. "Australian Product Information." O 0

3. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

Further information

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

Some side effects may not be reported. You may report them to the FDA.