Please wait...


Generic Name: methylnaltrexone (oral/injection) (METh IL nal TREX own)
Brand Names: Relistor
Relistor reduces constipation caused by narcotic medications used to treat pain in people with terminal illness . Learn about side effects, interactions and indications.
  • Prescription Settings

Prices and coupons of Relistor

Current Location: 20149 (Ashburn)
Change Location?

Enter your zip code

Please wait while the prices are loaded...

Don’t see your pharmacy listed? Most pharmacies accept our discounts, so have your pharmacist enter this coupon to see if you will save money:

Drug Information:
Relistor (methylnaltrexone) blocks the effects of opioid medication. An opioid is sometimes called a narcotic. Relistor reduces constipation caused by using narcotic medicine for 4 weeks or longer. Methylnaltrexone works by preventing constipation without reducing the pain-relieving effects of the narcotic. Relistor is given to adults who use narcotic medicine to treat severe chronic pain that is not caused by cancer. Relistor injection is also for use in adults who have advanced illness and are receiving palliative care (treatment to relieve suffering and improve quality of life during a serious illness). Learn more

Relistor Side Effects

Relistor Side Effects

Note: This document contains side effect information about methylnaltrexone. Some of the dosage forms listed on this page may not apply to the brand name Relistor.

For the Consumer

Applies to methylnaltrexone: oral tablet

Other dosage forms:

  • subcutaneous solution

Along with its needed effects, methylnaltrexone (the active ingredient contained in Relistor) 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

  • Chills
  • diarrhea
  • fear or nervousness
  • increased sweating
  • severe abdominal or stomach pain
  • severe or persistent diarrhea
  • yawning

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:

Less common

  • Full or bloated feeling
  • headache
  • muscle spasms
  • pressure in the stomach
  • runny nose
  • swelling of the abdominal or stomach area
  • vomiting

For Healthcare Professionals

Applies to methylnaltrexone: oral tablet, subcutaneous kit, subcutaneous solution


Very common (10% or more): Abdominal pain (up to 29%), flatulence (up to 13%), nausea (up to 12%)

Common (1% to 10%): Diarrhea,

Postmarketing reports: Perforation, cramping, vomiting

Nervous system

Common (1% to 10%): Dizziness, tremor


Common (1% to 10%): Hyperhidrosis, flushing


Common (1% to 10%): Chills

Postmarketing reports: Malaise, pain, cases of opioid withdrawal


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.

Frequency not reported: Myocardial infarctions


The most common adverse reactions included abdominal pain, nausea, diarrhea, hyperhidrosis, hot flush, tremor, and chills.


Common (1% to 10%): Injection site reactions including stinging, burning, pain, redness, and edema

Editorial References and Review

Medically reviewed by BestRx Medical Team Last updated on 1/1/2020.

Source: Drugs.com Relistor