Naltrexone

views updated Jun 08 2018

Naltrexone

Definition

Purpose

Description

Recommended dosage

Precautions

Side effects

Interactions

Resources

Definition

Naltrexone is classified as a pure opiate antagonist. It is sold in the United States under the brand names ReVia and Depade, but is also manufactured and sold under its generic name.

Purpose

Naltrexone is used as part of medically supervised behavior modification programs to help patients who have stopped taking narcotics or alcohol to continue to abstain from opiates or alcohol.

Description

Opiates are a group of drugs that are either derived from opium (i.e., morphine, hydromorphone, oxymor-phone, heroin, codeine, hydrocodone, oxycodone) or chemically resemble these opium derivatives (such as meperidine). They are commonly referred to as narcotics. Some opiates have medically valid uses, while others are recreational drugs of abuse. All are physically addictive.

The drug naltrexone is an opiate antagonist. This means that it blocks and reverses the physical effects of drugs such as morphine, hydromorphone, oxymor-phone, heroin, meperidine, codeine, hydrocodone, oxycodone and other drugs classified as narcotics. When given to patients who have been successfully treated for opiate addiction, it not only decreases cravings for these types of drugs, it also helps patients who use opiates while taking naltrexone to avoid experiencing the euphoria associated with their use. In these two ways, naltrexone helps prevent re-addiction to opiates.

Chemically naltrexone is not an alcohol antagonist. However, when it is used in combination with behavior modification in a person recovering from alcoholism, naltrexone decreases the craving for alcohol. This helps patients to prevent a return to alcohol use or decreases the severity of relapse by reducing the amount of alcohol consumed during the relapse or decreasing the length of the relapse.

Naltrexone is available in 50-mg oral tablets.

Recommended dosage

After successful detoxification from opiates, people who used them will receive a test dose of 25 mg of naltrexone, then be observed for one hour for symptoms of opiate withdrawal. If no problems occur after this test dose, another 25-mg test dose is administered.

Getting such people to comply with treatment for opiate addiction is the single most important aspect in maintaining an opiate-free state. Different schedules for taking naltrexone have been developed to help meet the needs of individuals complying with taking the drug. Following successful initiation of therapy, naltrexone may be administered in one of the following ways:

  • 50 mg daily, Monday through Friday, and 100 mg on Saturday
  • 100 mg every other day
  • 150 mg every third day
  • 100 mg on Monday and Wednesday and 150 mg on Friday
  • 150 mg on Monday and 200 mg on Thursday The duration of treatment with naltrexone for people with opiate dependence varies with patient need, although most patients will require at least six months of treatment.

The usual dose of naltrexone for alcohol dependence is 50 mg daily, although a few patients may require only 25 mg daily. The proper duration of therapy is not known, as studies of the use of naltrexone in people with alcohol dependence did not go beyond 12 weeks.

KEY TERMS

Antagonist —A substance whose actions counteract the effects of or work in the opposite way from another chemical or drug.

Opiates —A class of drugs that is either derived from opium (i.e., morphine, hydromorphone, oxymor-phone, heroin, codeine, hydrocodone, oxycodone) or resembles these opium derivatives (such as meper-idine) and is commonly referred to as narcotics.

Precautions

In a very small number of patients, naltrexone may be toxic and cause damage to the liver. Before starting naltrexone and throughout treatment, patients should receive monthly liver function tests to assess the drug’s effect on the liver.

Patients should be free of all opiates for seven to 10 days before starting naltrexone. Naltrexone may cause opiate withdrawal symptoms in people whose bodies are not free from opiates. Patients should be observed for opiate withdrawal immediately following the first dose of the drug.

Patients may have a false sense of security that the presence of naltrexone in their system makes them immune from the effects of opiates. In fact, the opiate antagonism caused by naltrexone is not absolute and patients can still experience both analgesia (suppression of pain) and euphoria by administration of larger-than-normal amounts of opiates. Consequently, patients receiving naltrexone who continue to use or receive opiates may take larger doses and should be monitored for signs and symptoms of opiate overdose.

Side effects

The following represents the most common side effects associated with naltrexone:

  • nausea, vomiting, diarrhea, cramps
  • headache, insomnia, anxiety, irritability, depression, dizziness
  • joint and muscle pain
  • rash

Interactions

Because naltrexone is an opiate antagonist, opiate derivatives that are used medicinally in treating coughs, diarrhea, and pain may no longer be effective.

The combination of naltrexone and disulfiram, a drug that is also used for alcohol abuse, may cause increased liver toxicity and liver damage. This combination should be avoided unless, in consultation with a physician, it is decided that the potential benefits of this combination outweigh the risks.

Resources

BOOKS

American Society of Health-System Pharmacists. AHFS Drug Information 2002. Bethesda: American Society of Health-System Pharmacists, 2002.

Preston, John D., John H. O’Neal, and Mary C. Talaga. Handbook of Clinical Psychopharmacology for Therapists. 4th ed. Oakland, CA: New Harbinger Publications, 2004.

PERIODICALS

Anton, Raymond F., and others. “Combined Pharmaco-therapies and Behavioral Interventions for Alcohol Dependence: The COMBINE Study: A Randomized Controlled Trial.” Journal of the American Medical Association 295.17 (May 2006): 2003–17.

Armeli, Stephen, and others. “The Effects of Naltrexone on Alcohol Consumption and Affect Reactivity to Daily Interpersonal Events Among Heavy Drinkers.” Experimental and Clinical Psychopharmacology 14.2 (May 2006): 199–208.

Comer, Sandra D., and others. “Injectable, Sustained-Release Naltrexone for the Treatment of Opioid Dependence: A Randomized, Placebo-Controlled Trial.” Archives of General Psychiatry 63.2 (Feb. 2006): 210–18.

Johansson, Bjőrn Axel, Mats Berglund, and Anna Lindgren. “Efficacy of Maintenance Treatment with Naltrexone for Opioid Dependence: A Meta-Analytical Review.” Addiction 101.4 (Apr. 2006): 491–503.

Morley, Kirsten C., and others. “Naltrexone Versus Acam-prosate in the Treatment of Alcohol Dependence: A Multi-Centre, Randomized, Double-Blind, Placebo-Controlled Trial.” Addiction 101.10 (Oct. 2006): 1451–62.

Nunes, Edward V., and others. “Behavioral Therapy to Augment Oral Naltrexone for Opioid Dependence: A Ceiling on Effectiveness?” American Journal of Drug and Alcohol Abuse 32.4 (2006): 503–17.

O’Brien, Charles, and James W. Cornish. “Naltrexone for Probationers and Parolees.” Journal of Substance Abuse Treatment 31.2 (Sept. 2006): 107–11.

Petrakis, Ismene L., and others. “Naltrexone and Disulfiram in Patients with Alcohol Dependence and Comorbid Post-Traumatic Stress Disorder.” Biological Psychiatry 60.7 (Oct. 2006): 777–83.

Pettinati, Helen M., and others. “The Status of Naltrexone in the Treatment of Alcohol Dependence: Specific Effects on Heavy Drinking.” Journal of Clinical Psychopharmacology 26.6 (Dec. 2006): 610–25.

Rohsenow, Damaris J., and others. “High-Dose Transder-mal Nicotine and Naltrexone: Effects on Nicotine Withdrawal, Urges, Smoking, and Effects of Smoking.” Experimental and Clinical Psychopharmacology 15.1 (Feb. 2007): 81–92.

Roozen, Hendrik Gand others. “A Systematic Review of the Effectiveness of Naltrexone in the Maintenance Treatment of Opioid and Alcohol Dependence.” European Neuropsychopharmacology 16.5 (July 2006): 311–23.

Sullivan, Maria A., and others. “Predictors of Retention in Naltrexone Maintenance for Opioid Dependence: Analysis of a Stage I Trial.” The American Journal on Addictions 15.2 (Mar.–Apr. 2006): 150–59.

Jack Raber, Pharm.D.
Ruth A. Wienclaw, PhD

Naltrexone

views updated Jun 27 2018

Naltrexone

Definition

Naltrexone is classified as a pure opiate antagonist. It is sold in the United States under the brand names ReVia and Depade, but is also manufactured and sold under its generic name.

Purpose

Naltrexone is used as part of medically supervised behavior modification programs in order to maintain a patient previously addicted to opiates in an opiate-free state following successful opiate detoxification . Naltrexone is also used in the management of alcohol dependence and abstinence in combination with medically supervised behavior modification programs.

Description

Opiates are a group of drugs that are either derived from opium (i.e. morphine, hydromorphone, oxymorphone, heroin, codeine, hydrocodone, oxycodone) or chemically resemble these opium derivatives (such as meperidine). They are commonly referred to as narcotics. Some opiates have medically valid uses, while others are recreational drugs of abuse. All are physically addictive.

The drug naltrexone is an opiate antagonist. This means that it blocks and reverses the physical effects of drugs such as morphine, hydromorphone, oxymorphone, heroin, meperidine, codeine, hydrocodone, oxycodone and other drugs classified as narcotics. When given to patients who have been successfully treated for opiate addiction , it not only decreases craving for these types of drugs, it also prevents patients who use opiates while taking naltrexone from experiencing the euphoria associated with their use. In these two ways, naltrexone helps prevent re-addiction to opiates.

Chemically, naltrexone is not an alcohol antagonist. However, when it is used in combination with behavior modification in the recovering alcoholic, naltrexone decreases the craving for alcohol. This helps to prevent a return to alcohol use, or it decreases the severity of relapse by reducing the amount of alcohol consumed during the relapse or decreasing the length of the relapse.

Naltrexone is available in 50-mg oral tablets.

Recommended dosage

After a person has been successfully detoxified from opiates, he or she will receive a test dose of 25 mg of naltrexone, then be observed for one hour for symptoms of opiate withdrawal. If no problems occur after this test dose, another 25 mg test dose is administered.

Getting a person to comply with treatment for opiate addiction is the single most important aspect in maintaining an opiate-free state. Different schedules for taking naltrexone have been developed to help meet the needs of individuals in order to make taking the drug easier. Following successful initiation of therapy, naltrexone may be administered in one of the following ways:

  • 50 mg daily Monday through Friday and 100 mg Saturday
  • 100 mg every other day
  • 150 mg every third day
  • 100 mg on Monday and Wednesday and 150 mg on Friday
  • 150 mg on Monday and 200 mg on Thursday

The duration of treatment with naltrexone for opiate dependence varies with patient need, although most patients will require at least six months of treatment.

The usual dose of naltrexone for alcohol dependence is 50 mg daily, although a few patients may require only 25 mg daily. The proper duration of therapy is not known, as studies of the use of naltrexone in alcohol dependence did not go beyond 12 weeks.

Precautions

In a very small number of patients, naltrexone may be toxic and cause damage to the liver. Before starting naltrexone and throughout treatment, patients should receive monthly liver function tests to assess the drug's effect on the liver.

Patients should be free of all opiates for seven to 10 days before starting naltrexone. Naltrexone may cause opiate withdrawal symptoms in people whose bodies are not free from opiates. Patients should be observed for opiate withdrawal immediately following the first dose of the drug.

Patients may have a false sense of security that the presence of naltrexone in their system makes them immune from the effects of opiates. In fact, the opiate antagonism caused by naltrexone is not absolute and patients can still experience both analgesia (suppression of pain) and euphoria by administration of larger-than-normal amounts of opiates. Consequently, patients receiving naltrexone who continue to use or receive opiates may take larger doses and should be monitored for signs and symptoms of opiate overdose.

Side effects

The following represents the most common side effects associated with naltrexone:

  • nausea, vomiting, diarrhea, cramps
  • headache, insomnia , anxiety, irritability, depression, dizziness
  • joint and muscle pain
  • rash

Interactions

Because naltrexone is an opiate antagonist, opiate derivatives that are used for medicinally in treating cough, diarrhea, and pain may no longer be effective.

The combination of naltrexone and disulfiram , a drug that is also used for alcohol abuse, may cause increased liver toxicity and liver damage when taken together. This combination should be avoided unless in consultation with a physician, it is decided that the potential benefits of this combination outweigh the risks.

Resources

BOOKS

American Society of Health-System Pharmacists. AHFS Drug Information 2002. Bethesda: American Society of Health-System Pharmacists, 2002.

O'Brien, Charles P. "Drug Addiction and Drug Abuse." In Goodman & Gillman's The Pharmacological Basis of Therapeutics Tenth Edition edited by Joel G. Hardman, Ph.D. and Lee E. Limbird, Ph.D. New York: McGraw-Hill, 2001.

Jack Raber, Pharm.D.

Naltrexone

views updated May 09 2018

Naltrexone

Naltrexone is a drug used to treat people who are dependent on opiate or opioid drugs such as heroin. Naltrexone has the ability to antagonize, or reverse, virtually all the effects of opiate/opioid drugs. It blocks the pleasurable or rewarding effects of opiate drugs, so that addicts do not feel a craving for the drugs. This antagonist effect is long lasting. In addition, naltrexone does not produce any pleasurable effects on its own. As a result, the patient has little incentive to misuse the medication and will not become dependent on it.

Treatment with naltrexone is most successful when combined with a program of counseling and other rehabilitation services. Addicts who are employed and able to manage their lives, and who are highly motivated to beat their addiction, have the best treatment results. This is especially true when addicts face severe economic or legal consequences for failing treatment. For example, health professionals with an addiction problem must get treatment in order to keep their medical licenses. These addicts typically take naltrexone regularly for several years (known as maintenance treatment) and remain abstinent from opiates. Some programs have reported five-year success rates as high as 95 percent. In contrast, most street addicts have unstable living situations and support their drug use through criminal activity. Typically, these addicts refuse to take naltrexone. If they do begin treatment, in general they quickly drop out. Naltrexone's ineffectiveness for this type of addict is probably due to the drug's lack of pleasurable effects. Many such addicts prefer maintenance treatment with methadone, an opiate drug that produces some desirable effects.

In the 1990s researchers studied naltrexone as a treatment for alcoholism. Alcoholic men who had gone through detoxification were given naltrexone. Naltrexone reduced the likelihood that these men would return to alcohol use. A 1999 study showed that naltrexone reduces the desire and craving for alcohol. However, it can sometimes increase the negative side effects, including headaches. Naltrexone is especially effective in the treatment of alcoholism when use of the drug is combined with therapy to change the patient's behavior. Naltrexone is also being studied experimentally as a possible treatment for cigarette smoking and eating disorders.

see also Alcohol Treatment: Medications; Heroin Treatment: Medications; Opiate and Opioid Drug Abuse; Tobacco Treatment: Medications.

naltrexone

views updated May 21 2018

naltrexone (nal-treks-ohn) n. an opioid antagonist drug used in the maintenance treatment of heroin- and other opioid-dependent patients. It is administered by mouth. Trade name: Nalorex.

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