methylnaltrexone (oral/injection)

What is the most important information I should know about methylnaltrexone?

What is methylnaltrexone?

Methylnaltrexone reduces constipation caused by using opioid medicine. Methylnaltrexone treats constipation without reducing the pain-relieving effects of the opioid.

Methylnaltrexone is given to adults who use opioid medicine to treat severe chronic pain that is not caused by cancer. Methylnaltrexone 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).

Methylnaltrexone may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before using methylnaltrexone?

Tell your doctor if you have ever had:

• a stomach ulcer;
• perforation (a hole or tear) in your stomach or intestines;
• kidney disease;
• liver disease; or
• colitis or other intestinal disorder such as Crohn's disease, diverticulitis, or Ogilvie's syndrome.

How should I use methylnaltrexone?

Stop using laxatives before you start using methylnaltrexone.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Methylnaltrexone can produce a bowel movement within 30 minutes. Be sure you are near a restroom when you use this medicine.

Methylnaltrexone oral is taken by mouth.

Methylnaltrexone injection is injected under the skin. A healthcare provider will give your first dose and may teach you how to properly use the medication by yourself.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you don't understand all instructions.

Your healthcare provider will show you where on your body to inject methylnaltrexone. Use a different place each time you give an injection. Do not inject into the same place two times in a row.

Prepare an injection only when you are ready to give it. Do not use if the medicine looks cloudy, has changed colors, or has particles in it. Call your pharmacist for new medicine.

Each methylnaltrexone injection vial (bottle) or prefilled syringe is for one use only. Throw it away after one use, even if there is still medicine left inside.

Do not use methylnaltrexone more often than once every 24 hours.

Use a needle and syringe only once and then place them in a puncture-proof "sharps" container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets.

After you stop using your opioid pain medication, you should also stop using methylnaltrexone.

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?

When you have an opioid medication in your system, an overdose of methylnaltrexone could stimulate opioid withdrawal symptoms. Common withdrawal symptoms are yawning, irritability, sweating, chills, vomiting, diarrhea, and body aches.

What should I avoid while using methylnaltrexone?

What are the possible side effects of methylnaltrexone?

• severe or ongoing diarrhea;
• extreme dizziness, or feeling like you might pass out;
• bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
• nausea or vomiting that are new or worsening symptoms; or
• symptoms of opioid medicine withdrawal --anxiety, sweating, chills, yawning, stomach pain, diarrhea.

Common side effects may include:

• stomach pain, gas, bloating;
• mild nausea or diarrhea;
• headache, muscle spasms;
• dizziness, tremors, feeling anxious;
• runny nose; or
• chills, sweating, or hot flashes.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect methylnaltrexone?

Other drugs may affect methylnaltrexone, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Where can I get more information?

Your doctor or pharmacist can provide more information about methylnaltrexone.