Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

  1. Relistor

Descriptions


Methylnaltrexone bromide is used to treat constipation caused by opioids (narcotic pain medicines), in adults with long-lasting pain that is not caused by cancer, or in patients with long-lasting pain caused by a previous cancer or its treatment who do not need weekly increases in opioid dosage.

This medicine is available only with your doctor's prescription.

This product is available in the following dosage forms:

  • Tablet

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of methylnaltrexone in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of methylnaltrexone in the elderly. However, elderly patients are more likely to have diarrhea, which may require caution in the dose for patients receiving this medicine.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Morphine
  • Morphine Sulfate Liposome
  • Naldemedine
  • Naloxegol
  • Oxycodone
  • Oxymorphone

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Crohn's disease or
  • Diverticulitis or
  • Ogilvie's syndrome (decreased movement of food in the intestines) or
  • Peptic ulcer or
  • Stomach or bowel cancer—May increase risk for more serious side effects.
  • Liver disease or
  • Kidney disease, severe—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
  • Stomach or bowel blockage, known, suspected, or increased risk of—Should not be used in patients with these conditions.

Proper Use

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of side effects.

This medicine comes with a Medication Guide. Read and follow these instructions carefully. Ask your doctor if you have any questions.

Take this medicine with water on an empty stomach at least 30 minutes before the first meal of the day.

Stop taking other laxatives before starting treatment with methylnaltrexone. You should also stop using this medicine if you have stopped taking narcotic pain medicines.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (tablets):
    • For constipation caused by opioids in patients with chronic non-cancer pain:
      • Adults—450 milligrams (mg) once a day in the morning for at least 4 weeks (with narcotic pain medicines).
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Keep out of the reach of children.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to use it.

This medicine may cause a tear (perforation) in your stomach or bowels. Check with your doctor right away if you have a severe stomach pain that does not go away.

If severe or persistent (non-stop) diarrhea occurs while using this medicine, check with your doctor right away.

Do not suddenly stop using this medicine without checking first with your doctor. Doing so may cause withdrawal symptoms, such as anxiety, chills, increased tearing, redness on the face, neck, arms, and upper chest, feeling cold, diarrhea, irritability, stomach pain, increased sweating, and yawning.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects

Along with its needed effects, a medicine 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:

Incidence not known

  1. Chills
  2. diarrhea
  3. fear or nervousness
  4. increased sweating
  5. severe abdominal or stomach pain
  6. severe or persistent diarrhea
  7. yawning

Some side effects 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

  1. Full or bloated feeling
  2. headache
  3. muscle spasms
  4. pressure in the stomach
  5. runny nose
  6. swelling of the abdominal or stomach area
  7. vomiting

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Portions of this document last updated: Feb. 01, 2024

Original article: https://www.mayoclinic.org/ar/drugs-supplements/methylnaltrexone-bromide-oral-route/precautions/drg-20312349