Relistor oral / injection

Methylnaltrexone blocks the effects of opioid medication. An opioid is sometimes called a narcotic.

Methylnaltrexone 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.

Methylnaltrexone is given to adults who use narcotic 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 is usually given after laxatives have been tried without successful treatment of constipation.

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

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.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

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.

Do not use any other laxatives that your doctor has not prescribed.

You should not use Relistor if you are allergic to methylnaltrexone, or if you have:

• a blockage in your stomach or intestines.

To make sure Relistor is safe for you, tell your doctor if you have ever had:

• cancer;

• a stomach ulcer;

• a perforation (hole or tear) in stomach or intestines;

• kidney disease; or

• colitis or other intestinal disorder such as Crohn's disease, diverticulitis, or Ogilvie's syndrome.

It is not known whether Relistor will harm an unborn baby. If you use this medicine while you are pregnant, your baby could become dependent on the drug. This can cause life-threatening withdrawal symptoms in the baby after it is born. Babies born dependent on habit-forming medicine may need medical treatment for several weeks. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether methylnaltrexone passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

Relistor is not approved for use by anyone younger than 18 years old.

Usual Adult Dose for Constipation - Chronic:

Opioid-Induced Constipation in Patients with Chronic Non-Cancer Pain:
12 mg subcutaneously once a day

Comments: Prior to initiation, discontinue all maintenance laxative therapy; laxatives can be used as needed for suboptimal response after 3 days.

Opioid-Induced Constipation in Patients with Advanced Illness:
-One-dose subcutaneously every other day as needed, but no more frequently than 1 dose in a 24-hour period; weight-based dosing as follows:
Less than 38 kg: 0.15 mg/kg
38 kg to less than 62 kg: 8 mg (0.4 mL)
62 kg to 114 kg: 12 mg subcutaneously (0.6 mL)
More than 114 kg: 0.15 mg/kg subcutaneously

Comments: To determine injection volume for patients whose weight is less than 38 kg or more than 114 kg: multiply patient weight (kg) by 0.0075 and round up to the nearest 0.1 mL

Uses:
-For the treatment of opioid-induced constipation in adult patients with chronic non-cancer pain.
-For the treatment of opioid-induced constipation in adult patients with advanced illness who are receiving palliative care, when response to laxative therapy has not been sufficient.

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.

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

Gastrointestinal

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[Ref]

Nervous system

Common (1% to 10%): Dizziness, tremor[Ref]

Dermatologic

Common (1% to 10%): Hyperhidrosis, flushing[Ref]

Other

Common (1% to 10%): Chills
Postmarketing reports: Malaise, pain, cases of opioid withdrawal[Ref]

Cardiovascular

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.[Ref]

Frequency not reported: Myocardial infarctions[Ref]

General

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

Local

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

Some side effects of Relistor may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.