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Some commonly used brand names are:

In the U.S.—

  • ReVia

In Canada—

  • ReVia

Generic name product may be available in the U.S.


  • Opioid (narcotic) abuse therapy adjunct
  • Opioid (narcotic) antagonist
  • Alcohol abuse therapy adjunct


Naltrexone (nal-TREK-zone) is used to help narcotic addicts who have stopped taking narcotics to stay drug-free. It is also used to help alcoholics stay alcohol-free. The medicine is not a cure for addiction. It is used as part of an overall program that may include counseling, attending support group meetings, and other treatment recommended by your doctor.

Naltrexone is not a narcotic. It works by blocking the effects of narcotics, especially the ``high"" feeling that makes you want to use them. It also may block the ``high"" feeling that may make you want to use alcohol. It will not produce any narcotic-like effects or cause mental or physical dependence. It will not prevent you from becoming impaired while drinking alcohol.

Naltrexone will cause withdrawal symptoms in people who are physically dependent on narcotics. Therefore, naltrexone treatment is started after you are no longer dependent on narcotics. The length of time this takes may depend on which narcotic you took, the amount you took, and how long you took it. Before you start taking this medicine, be sure to tell your doctor if you think you are still having withdrawal symptoms.

Naltrexone is available only with your doctor"s prescription, in the following dosage form:

  • Oral
  • Tablets (U.S. and Canada)

Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For naltrexone, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to naltrexone. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Naltrexone has not been studied in pregnant women. However, studies in animals have shown that naltrexone causes unwanted effects when given in very large doses. Before taking this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding—It is not known whether naltrexone passes into the breast milk. However, this medicine has not been reported to cause problems in nursing babies.

Children—Naltrexone has been tested only in adult patients and there is no specific information about its use in patients up to 18 years of age.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing the use of naltrexone in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking naltrexone, it is especially important that your health care professional know if you are taking any of the following:

  • Opioid (Narcotic) analgesics (e.g., butorphanol [e.g., Stadol], codeine, hydrocodone [e.g., Hycodan], hydromorphone [e.g., Dilaudid], levorphanol [e.g., Levo-Dromoran], meperidine [e.g., Demerol], methadone [e.g., Dolophine], morphine [e.g., MSIR], nalbuphine [e.g., Nubain], oxycodone [e.g., Roxicodone], propoxyphene [e.g., Darvon]) or
  • Opioid-containing medications, other—The effects of these medications may be blocked by naltrexone. Alternative medications for relief of pain should be used in patients receiving naltrexone. Naltrexone may cause withdrawal in patients dependent on narcotics.

Other medical problems—The presence of other medical problems may affect the use of naltrexone. Make sure you tell your doctor if you have any other medical problems, especially:

  • Hepatitis or other liver disease—The chance of side effects may be increased

Proper Use of This Medicine

Take naltrexone regularly as ordered by your doctor . It may be helpful to have someone else, such as a family member, doctor, or nurse, give you each dose as scheduled.

Dosing—The dose of naltrexone will be different for different patients. Follow your doctor"s orders or the directions on the label . The following information includes only the average doses of naltrexone. If your dose is different, do not change it unless your doctor tells you to do so.

  • For oral dosage form (tablets):
    • For treating narcotic addiction:
      • Adults—25 milligrams (mg) (one-half tablet) for the first dose, then another 25 mg one hour later. After that, the dose is 350 mg a week. Your doctor will direct you to divide up this weekly dose and take naltrexone according to one of the following schedules:
        • 50 mg (one tablet) every day; or
        • 50 mg a day during the week and 100 mg (two tablets) on Saturday; or
        • 100 mg every other day; or
        • 100 mg on Mondays and Wednesdays, and 150 mg (three tablets) on Fridays; or
        • 150 mg every three days.
      • Children and teenagers up to 18 years of age—Use and dose must be determined by your doctor.
    • For treating alcoholism:
      • Adults—The first dose may be 25 milligrams (mg) (one-half tablet). After that, the dose is 50 mg (one tablet) every day.
      • Children and teenagers up to 18 years of age—Use and dose must be determined by your doctor.

Missed dose—If you miss a dose of this medicine, and your regular dosing schedule is:

  • One tablet every day:
    • Take the missed dose as soon as possible. However, if you do not remember until the next day, skip the missed dose and go back to your regular dosing schedule. Do not double the next day"s dose.
  • One tablet every weekday and two tablets on Saturday:
    • If you miss a weekday dose, follow the directions for one tablet every day.
    • If you miss the Saturday dose, take it as soon as possible. However, if you do not remember until Sunday, take one tablet on Sunday. Then go back to your regular dosing schedule on Monday.
  • Two tablets every other day:
    • Take two tablets as soon as you remember, then skip a day, then go back to taking the medicine every other day; or
    • Take two tablets as soon as possible if you remember the same day. However, if you do not remember until the next day, take one tablet the next day. Then go back to your regular dosing schedule.
  • Two tablets on Monday and Wednesday and three tablets on Friday:
    • If you miss one of the Monday or Wednesday doses, take it as soon as possible. However, if you do not remember until the next day, take one tablet the next day. Then go back to your regular dosing schedule.
    • If you miss the Friday dose, take it as soon as possible if you remember the same day. However, if you do not remember until Saturday, take two tablets on Saturday. If you do not remember until Sunday, take one tablet on Sunday. Then go back to your regular dosing schedule on Monday.
  • Three tablets every three days:
    • Take three tablets as soon you remember, then skip two days, then go back to taking the medicine every three days; or
    • Take three tablets as soon as possible if you remember the same day. However, if you do not remember until the next day, take two tablets, then skip a day and go back to your regular dosing schedule. If you do not remember until the second day, take one tablet. Then go back to your regular dosing schedule.

Storage—To store this medicine:

  • Keep out of the reach of children.
  • Store away from heat and direct light.
  • Do not store this medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
  • Do not keep outdated medicine.

Precautions While Using This Medicine

It is very important that your doctor check your progress at regular visits . Your doctor may want to do certain blood tests to see if the medicine is causing unwanted effects.

Remember that use of naltrexone is only part of your treatment. Be sure that you follow all of your doctor"s orders, including seeing your therapist and/or attending support group meetings on a regular basis .

Do not try to overcome the effects of naltrexone by taking narcotics . To do so may cause coma or death. You may be more sensitive to the effects of narcotics than you were before beginning naltrexone therapy.

Naltrexone also blocks the useful effects of narcotics. Always use a non-narcotic medicine to treat pain, diarrhea, or cough . If you have any questions about the proper medicine to use, check with your health care professional.

Naltrexone will not prevent you from becoming impaired when you drink alcohol. Do not take naltrexone in order to drive or perform other activities while under the influence of alcohol .

Never share this medicine with anyone else, especially someone who is using narcotics . Naltrexone causes withdrawal symptoms in people who are using narcotics.

Tell all medical doctors, dentists, and pharmacists you go to that you are taking naltrexone .

It is recommended that you carry identification stating that you are taking naltrexone . Identification cards may be available from your doctor.

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

Less common

Skin rash


Abdominal or stomach pain (severe); blurred vision or aching, burning, or swollen eyes; chest pain; confusion; discomfort while urinating and/or frequent urination; fever; hallucinations (seeing, hearing, or feeling things that are not there); itching; mental depression or other mood or mental changes; ringing or buzzing in ears; shortness of breath; swelling of face, feet, or lower legs; weight gain

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

More common

Abdominal or stomach cramping or pain (mild or moderate); anxiety, nervousness, restlessness, and/or trouble in sleeping; headache; joint or muscle pain; nausea or vomiting; unusual tiredness

Less common or rare

Chills; constipation; cough, hoarseness, runny or stuffy nose, sinus problems, sneezing, and/or sore throat; diarrhea; dizziness; fast or pounding heartbeat; increased thirst; irritability; loss of appetite; sexual problems in males

Other side effects not listed above, possibly including withdrawal symptoms, may also occur in some patients. If you notice any other effects, check with your doctor.

Revised: 08/13/97
Interim revision: 07/07/98

The information contained in the Thomson Healthcare (Micromedex) products as delivered by is intended as an educational aid only. It is not intended as medical advice for individual conditions or treatment. It is not a substitute for a medical exam, nor does it replace the need for services provided by medical professionals. Talk to your doctor, nurse or pharmacist before taking any prescription or over the counter drugs (including any herbal medicines or supplements) or following any treatment or regimen. Only your doctor, nurse, or pharmacist can provide you with advice on what is safe and effective for you.

The use of the Thomson Healthcare products is at your sole risk. These products are provided "AS IS" and "as available" for use, without warranties of any kind, either express or implied. Thomson Healthcare and make no representation or warranty as to the accuracy, reliability, timeliness, usefulness or completeness of any of the information contained in the products. Additionally, THOMSON HEALTHCARE MAKES NO REPRESENTATION OR WARRANTIES AS TO THE OPINIONS OR OTHER SERVICE OR DATA YOU MAY ACCESS, DOWNLOAD OR USE AS A RESULT OF USE OF THE THOMSON HEALTHCARE PRODUCTS. ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE OR USE ARE HEREBY EXCLUDED. Thomson Healthcare does not assume any responsibility or risk for your use of the Thomson Healthcare products.

Where can I get more information about Naltrexone ? We recommend to use

Typical mistypes for Naltrexone
baltrexone, maltrexone, jaltrexone, haltrexone, nzltrexone, nsltrexone, nwltrexone, nqltrexone, naktrexone, naptrexone, naotrexone, nalrrexone, nalfrexone, nalgrexone, nalyrexone, nal6rexone, nal5rexone, nalteexone, naltdexone, naltfexone, nalttexone, nalt5exone, nalt4exone, naltrwxone, naltrsxone, naltrdxone, naltrrxone, naltr4xone, naltr3xone, naltrezone, naltrecone, naltredone, naltresone, naltrexine, naltrexkne, naltrexlne, naltrexpne, naltrex0ne, naltrex9ne, naltrexobe, naltrexome, naltrexoje, naltrexohe, naltrexonw, naltrexons, naltrexond, naltrexonr, naltrexon4, naltrexon3, altrexone, nltrexone, natrexone, nalrexone, naltexone, naltrxone, naltreone, naltrexne, naltrexoe, naltrexon, anltrexone, nlatrexone, natlrexone, nalrtexone, nalterxone, naltrxeone, naltreoxne, naltrexnoe, naltrexoen, nnaltrexone, naaltrexone, nalltrexone, nalttrexone, naltrrexone, naltreexone, naltrexxone, naltrexoone, naltrexonne, naltrexonee, etc.

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