Generic Name: Methylnaltrexone Injection (meth il nal TREKS one)
Brand Name: Relistor
Medically reviewed on July 4, 2018
Uses of Methylnaltrexone Injection:
- It is used to treat constipation caused by some pain drugs.
What do I need to tell my doctor BEFORE I take Methylnaltrexone Injection?
- If you have an allergy to methylnaltrexone or any other part of methylnaltrexone injection.
- If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
- If you have ever had bowel block.
- If you are taking or will be taking another drug like this one.
- If you are breast-feeding. Do not breast-feed while you take methylnaltrexone injection.
This is not a list of all drugs or health problems that interact with methylnaltrexone injection.
Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take methylnaltrexone injection with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
What are some things I need to know or do while I take Methylnaltrexone Injection?
- Tell all of your health care providers that you take methylnaltrexone injection. This includes your doctors, nurses, pharmacists, and dentists.
- Be sure to stay close to a bathroom after you use methylnaltrexone injection. Most people have a stool within a few minutes to a few hours after using it.
- Talk with your doctor before using a laxative with methylnaltrexone injection.
- This medicine is only for use in patients who take pain drugs. Tell your doctor if you stop taking your pain drug.
- Signs of opioid withdrawal have happened with methylnaltrexone injection. Call your doctor right away if you have more sweating, chills, loose stools (diarrhea) or stomach pain that is not normal, anxiety, irritability, or yawning.
- This medicine may not work as well for people who have been taking pain drugs for less than 4 weeks.
- If you are 65 or older, use methylnaltrexone injection with care. You could have more side effects.
- Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using methylnaltrexone injection while you are pregnant.
- If methylnaltrexone injection is used during pregnancy, it may cause withdrawal in the unborn baby. A doctor will need to check on the unborn baby after methylnaltrexone injection is used.
How is this medicine (Methylnaltrexone Injection) best taken?
Use methylnaltrexone injection as ordered by your doctor. Read all information given to you. Follow all instructions closely.
- It is given as a shot into the fatty part of the skin on the top of the thigh, belly area, or upper arm.
- If you will be giving yourself the shot, your doctor or nurse will teach you how to give the shot.
- Follow how to use as you have been told by the doctor or read the package insert.
- Wash your hands before and after use.
- Move the site where you give the shot with each shot.
- Do not give into red or irritated skin.
- Do not use if the solution is cloudy, leaking, or has particles.
- This medicine is colorless to a faint yellow. Do not use if the solution changes color.
- Throw away needles in a needle/sharp disposal box. Do not reuse needles or other items. When the box is full, follow all local rules for getting rid of it. Talk with a doctor or pharmacist if you have any questions.
What do I do if I miss a dose?
- If you take methylnaltrexone injection on a regular basis, take a missed dose as soon as you think about it.
- If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
- Do not take 2 doses at the same time or extra doses.
- Many times methylnaltrexone injection is taken on an as needed basis. Do not take more often than told by the doctor.
See also: Dosage Information (in more detail)
What are some side effects that I need to call my doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Very loose stools (diarrhea).
- Loose stools (diarrhea) that will not go away.
- Tears in the stomach or bowel wall have happened in certain people taking methylnaltrexone injection. Call your doctor right away if you have swelling or pain in your stomach that is very bad, gets worse, or does not go away. Call your doctor right away if you throw up blood or have throw up that looks like coffee grounds; upset stomach or throwing up that does not go away; or black, tarry, or bloody stools.
What are some other side effects of Methylnaltrexone Injection?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Belly pain.
- Loose stools (diarrhea).
- Sweating a lot.
- Upset stomach.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.
See also: Side effects (in more detail)
If OVERDOSE is suspected:
If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
How do I store and/or throw out Methylnaltrexone Injection?
- Store at room temperature.
- Store in a dry place. Do not store in a bathroom.
- Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
- Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
- Do not freeze.
- Protect from light.
- If methylnaltrexone injection is drawn from a vial into a syringe, it may be stored in the syringe at room temperature for up to 24 hours.
- Throw away any part of opened vial not used after use.
Consumer information use
- If your symptoms or health problems do not get better or if they become worse, call your doctor.
- Do not share your drugs with others and do not take anyone else's drugs.
- Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
- Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
- This medicine comes with an extra patient fact sheet called a Medication Guide. Read it with care. Read it again each time methylnaltrexone injection is refilled. If you have any questions about methylnaltrexone injection, please talk with the doctor, pharmacist, or other health care provider.
- If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
More about methylnaltrexone
- Methylnaltrexone Side Effects
- During Pregnancy
- Dosage Information
- En Español
- 39 Reviews
- Drug class: peripheral opioid receptor antagonists
- Methylnaltrexone oral/injection
- Methylnaltrexone Tablets
- Methylnaltrexone Subcutaneous (Advanced Reading)
- Methylnaltrexone bromide (Advanced Reading)
Other brands: Relistor