Naloxegol Side Effects

Medically reviewed by Drugs.com. Last updated on Apr 6, 2025.

Applies to naloxegol: oral tablet.

Common side effects of naloxegol

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 side effects

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

Less common side effects

• headache
• vomiting

Serious side effects of naloxegol

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 side effects

• 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

For healthcare professionals

Applies to naloxegol: oral tablet.

General adverse events

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

Other

• 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]

Gastrointestinal

• 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]

Dermatologic

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

Nervous system

• Common (1% to 10%): Headache^[Ref]

Respiratory

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

Frequently asked questions

• Which drugs cause opioid-induced constipation?

Further information

Naloxegol side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer