Relistor (methylnaltrexone) is a special narcotic drug that blocks certain effects of other narcotic medicines.
Relistor reduces constipation caused by opioid (narcotic) pain medicine used to treat severe chronic pain. Methylnaltrexone works by preventing constipation without reducing the pain-relieving effects of the narcotic.
Relistor is used in people with chronic pain that is not caused by cancer, or pain that is caused by advanced terminal illness.
Relistor is usually given after laxatives have been tried without successful treatment of constipation.
Important information
You should not use Relistor if you have a blockage in your stomach or intestines.
Before you use Relistor, tell your doctor if you have severe or ongoing diarrhea.
Prepare your Relistor dose in a syringe only when you are ready to give yourself an injection. After loading a syringe, if you cannot give the injection right away keep it at room temperature and use it within 24 hours.
Before receiving this medicine
You should not use Relistor if you are allergic to methylnaltrexone, or if you have:
To make sure Relistor is safe for you, tell your doctor if you have:
FDA pregnancy category B. Relistor is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.
See also: Pregnancy and breastfeeding warnings (in more detail)
It is not known whether methylnaltrexone passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
How is Relistor used?
Relistor is injected under the skin. You may be shown how to use injections at home. Do not self inject this medicine if you do not understand how to give the injection and properly dispose of used needles and syringes.
This medicine is usually given once every other day, but not more often than once every 24 hours.
Relistor can produce a bowel movement within 30 minutes after injection.
Prepare your dose in a syringe only when you are ready to give yourself an injection. After loading a syringe, if you cannot give the injection right away keep it at room temperature and use it within 24 hours.
Each single use vial (bottle) of this medicine is for one use only. Throw away after one use, even if there is still some medicine left in it after injecting your dose.
Use a disposable needle and syringe only once. Follow any state or local laws about throwing away used needles and syringes. Use a puncture-proof "sharps" disposal container (ask your pharmacist where to get one and how to throw it away). Keep this container out of the reach of children and pets.
Relistor should look clear or slightly yellow in color. Do not use the medication if it has changed colors or has particles in it. Call your doctor for a new prescription.
Store at room temperature away from moisture, heat, and light. Do not freeze.
Relistor dosing information
Usual Adult Dose for Constipation -- Chronic:
Less than 38 kg: 0.15 mg/kg subcutaneously every other day as needed
38 to less than 62 kg: 8 mg subcutaneously every other day as needed
62 to 114 kg: 12 mg subcutaneously every other day as needed
More than 114 kg: 0.15 mg/kg subcutaneously every other day as needed
The usual schedule is one dose every other day, as needed, but no more frequently than one dose in a 24-hour period.
What happens if I miss a dose?
Use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.
Do not use this medicine more than once in a 24-hour period.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid while using Relistor?
Do not use any other laxatives that your doctor has not prescribed.
Relistor side effects
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
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extreme dizziness, or feeling like you might pass out;
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ongoing diarrhea or stomach pain that will not go away;
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bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
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nausea or vomiting that are new or worsening symptoms; or
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symptoms of narcotic medicine withdrawal - anxiety, sweating, chills, yawning, stomach pain, diarrhea.
Common Relistor side effects may include:
This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
What other drugs will affect Relistor?
Other drugs may interact with methylnaltrexone, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.
