MedlinePlus Drug Information: Naltrexone

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Other drug names:	A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 0-9

Naltrexone

(nal trex' one)

Contents of this page:
Why is this medication prescribed? How should this medicine be used? What special precautions should I follow? What should I do if I forget a dose? What side effects can this medication cause?	What storage conditions are needed for this medicine? In case of emergency/overdose What other information should I know? Brand names

IMPORTANT WARNING: Return to top

Large doses of naltrexone may cause liver failure. Tell your doctor if you have liver or kidney disease. If you experience the following symptoms, stop taking naltrexone and call your doctor immediately: excessive tiredness, unusual bleeding or bruising, loss of appetite, pain in the upper right part of your stomach, dark urine, or yellowing of the skin or eyes.

Why is this medication prescribed? Return to top

Naltrexone is used to help people who have a narcotic or alcohol addiction stay drug free. Naltrexone is used after the patient has stopped taking drugs or alcohol. It works by blocking the effects of narcotics or by decreasing the craving for alcohol.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used? Return to top

Naltrexone comes as a tablet to take by mouth. It usually is taken once a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take naltrexone exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Naltrexone helps decrease the craving for narcotics or alcohol but does not treat addiction. It is important that you attend all counseling, support group meetings, and other treatments prescribed by your doctor. Take naltrexone regularly. Do not stop taking it without talking to your doctor.

If, in the past 7-10 days, you have taken opioids (morphine, codeine, or others; ask your doctor or pharmacist for more information), tell your doctor before taking the first dose of naltrexone. Naltrexone will cause withdrawal if you have opioids in your blood.

Your doctor may perform a challenge test before you begin taking naltrexone. A small dose of naloxone (a drug similar to naltrexone) will be injected into your vein or under your skin, and you will be watched for symptoms of drug withdrawal. If you have symptoms, you will need to wait a few days before beginning naltrexone.

You should take naltrexone as directed by your physician. If you take heroin or any other opioid in small doses, you will not perceive any effect. Do not take large doses of heroin or any other narcotic; you may die or sustain serious injury, including coma.

What special precautions should I follow? Return to top

Before taking naltrexone,

tell your doctor and pharmacist if you are allergic to naltrexone, other narcotics, or any other drugs.
tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially anti-diarrhea drugs, medications for cough and colds, pain medication, and vitamins.
tell your doctor if you have either of the conditions listed in the IMPORTANT WARNING section.
tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking naltrexone, call your doctor.
if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking naltrexone.
you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how this drug affects you.
remember that alcohol can add to the drowsiness caused by this drug.
you should know that if you take small doses of heroin or other narcotics while taking naltrexone, you will not feel any effects. If you take large doses of heroin or other narcotics while taking naltrexone, you may die, go into a coma, or have other serious injuries.

What should I do if I forget a dose? Return to top

If you miss your daily dose, take the missed dose as soon as you remember it. However, if you do not remember until the next day, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

If you are on a different dosing schedule, check with your pharmacist, nurse, or doctor.

What side effects can this medication cause? Return to top

Naltrexone may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

upset stomach
anxiety
nervousness
muscle or joint pain

If you experience any of the following symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately:

confusion
drowsiness
hallucinations
vomiting
diarrhea
bone and joint pain
skin crawling
stomach pain
white bowel movements
skin rash
blurred vision

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/MedWatch/index.html] or by phone [1-800-332-1088].

What storage conditions are needed for this medicine? Return to top

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose Return to top

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know? Return to top

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to naltrexone.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names Return to top

Depade®

ReVia® (formerly Trexan®;

Last Revised - 04/01/2003
Last Reviewed - 08/01/2007

American Society of Health-System Pharmacists, Inc. Disclaimer