Methylnaltrexone Side Effects
Medically reviewed by Drugs.com. Last updated on June 26, 2020.
For the Consumer
Applies to methylnaltrexone: oral tablet
Other dosage forms:
Side effects requiring immediate medical attention
Along with its needed effects, methylnaltrexone 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 methylnaltrexone:
Incidence not known
- fear or nervousness
- increased sweating
- severe abdominal or stomach pain
- severe or persistent diarrhea
Side effects not requiring immediate medical attention
Some side effects of methylnaltrexone 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:
- Full or bloated feeling
- muscle spasms
- pressure in the stomach
- runny nose
- swelling of the abdominal or stomach area
For Healthcare Professionals
Applies to methylnaltrexone: oral tablet, subcutaneous kit, subcutaneous solution
Common (1% to 10%): Diarrhea,
Postmarketing reports: Perforation, cramping, vomiting[Ref]
Common (1% to 10%): Dizziness, tremor[Ref]
Common (1% to 10%): Chills
In an open-label, uncontrolled study (n=1034), 4 myocardial infarctions (1 fatal), 1 stroke (fatal), 1 fatal cardiac arrest, and 1 sudden death were reported. It is not possible to establish a relationship between these events and use of this drug.[Ref]
Frequency not reported: Myocardial infarctions[Ref]
The most common adverse reactions included abdominal pain, nausea, diarrhea, hyperhidrosis, hot flush, tremor, and chills.[Ref]
1. Cerner Multum, Inc. "Australian Product Information." O 0
2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
3. "Product Information. Relistor (methylnaltrexone)." Wyeth Laboratories, Philadelphia, PA.
More about methylnaltrexone
- During Pregnancy
- Dosage Information
- Drug Interactions
- En Español
- 56 Reviews
- Drug class: peripheral opioid receptor antagonists
- Patient Information
- Methylnaltrexone Subcutaneous (Advanced Reading)
- Methylnaltrexone bromide (Advanced Reading)
- Methylnaltrexone Tablets
- Methylnaltrexone Injection
- Other brands
Related treatment guides
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.