Naltrexone Addiction Treatment

If you are in recovery from an alcohol or opioid addiction, you might be prescribed naltrexone. This is a drug that is used to help with the maintenance of sobriety. If you, or a loved one, are going to begin treatment inclusive of this medication, you may want to know more about it.

What Is Naltrexone?

Naltrexone blocks the feelings of well-being associated with mood-altering chemicals such as opioids and alcohol. It inhibits the need to use substances like heroin and quells the desire to drink. It is not used to treat the effects of drugs and is typically administered only to those who have already completed a detox programme.

As mentioned above, it is primarily utilised to help with a sobriety maintenance programme. As it is an opioid antagonist, it blocks the positive effects of alcohol abuse and encourages the person to stay sober. As a side-note, the drug is also often used off-label as a treatment for obesity.

Brand Names

  • ReVia
  • Vivitrol
  • Abernil
  • Naltax
  • Antaxon
  • Trexan
  • Neksi
  • Narcoral
  • Antaxone
  • Dependex
  • Nalerona

History of Naltrexone

Naltrexone was first developed in 1963 in New York, at Endo Laboratories. In 1965, it was discovered that it was a very powerful opioid antagonist that was orally active and long-lasting. The longer-acting properties of the drug meant that it had the advantage of needing to be administered only once per day. These discoveries then led to further research being carried out.

In 1967, the drug was patented under

the code name EN-1639A by Endo Laboratories, which was then acquired by DuPont in 1969.

In 1973, clinical trials on the use of the drug for opioid dependence began. The following year, DuPont collaborated with the National Institute on Drug Abuse on the development of the drug for this purpose.

In 1984, the US FDA approved the use of naltrexone for opioid dependence under the brand name Trexan. It was then approved for the treatment of alcohol dependence in 1995 when the trade name was changed to ReVia.

What Substance Abuse/Addictions Is Naltrexone Used to Treat?

  • Alcohol Addiction
  • Opioid Addiction

Is Naltrexone Addictive?

Naltrexone is not an addictive drug and there is no potential for abuse. In fact, naltrexone works by blocking the euphoric feelings associated with certain mood-altering chemicals.

What Is the Mechanism of Action?

The mechanism of action of naltrexone in the treatment of alcoholism is not fully understood. However, it is an opiate antagonist and it is believed that it binds to the opioid receptors in the brain to block the pleasurable effects of such drugs. The effects of opioid drugs, such as euphoria, drug craving, and respiratory depression, are suppressed by naltrexone.

How Long Does It Take for Naltrexone to Work?

The effects of naltrexone tend to appear after around thirty minutes of ingestion. However, it may take a number of weeks before there is a noticeable decrease in the desire for opioid drugs.

Does Naltrexone Have Any Interactions?

There are 534 drugs that are known to interact with naltrexone of which 132 cause a major interaction and 402 a moderate interaction.

There is an elevated risk of liver problems when naltrexone is used. Therefore, it is not recommended that naltrexone is used with any other substance that can cause liver problems, such as alcohol. Signs of liver damage include:

  • vomiting
  • abdominal pain
  • unusual bleeding
  • joint pain or swelling
  • itching
  • skin rash
  • loss of appetite
  • nausea
  • fatigue
  • yellowing of the skin and eyes
  • dark urine
  • pale stools

If you notice any of these symptoms when taking naltrexone, you should contact your doctor immediately.

Naltrexone can also cause problems in those patients with kidney dysfunction, so it is important that caution is taken when prescribing this medication to individuals with a history of kidney problems.

Should Any Precautions Be Taken?

Naltrexone is designed for use in patients who have completed an alcohol or opioid detox. It should not be used by those who are experiencing withdrawal symptoms from these substances or by those who have used opioid medication in the previous two weeks. Doing so could cause severe and sudden withdrawal symptoms.

Naltrexone is not recommended for use in anyone under the age of eighteen.

It is not known if naltrexone can harm an unborn baby, so use of the drug while pregnant should be avoided unless on the advice of a doctor. Also, speak to your doctor if you are pregnant or planning to become pregnant. Should you fall pregnant while taking naltrexone, contact your doctor immediately.

Naltrexone can pass to a nursing child through breast milk, which could potentially cause harm to your baby. You should, therefore, avoid breastfeeding while taking naltrexone.

It is important that your safety is fully considered before administering naltrexone. As such, you should inform your doctor if you have, or have ever had, any of the following health problems:

  • Liver disease
  • Kidney disease
  • Haemophilia or another blood-clotting disorder

Before taking naltrexone, you should inform your doctor of any medication you are currently taking. This is due to the above-mentioned potential for certain drugs to cause an interaction. Thus, you should tell your doctor about any birth-control pills, herbal products, vitamin supplements, prescription drugs, and over-the-counter medication that you are taking.

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What Are the Side Effects of Naltrexone?

While most side effects associated with naltrexone are mild and do not require any medical attention, you should speak to your doctor should any symptoms become severe or persistent. Below are some of the side effects that you might experience while taking this drug:

  • Drowsiness
  • Anxiety
  • Headaches
  • Fatigue
  • Nausea
  • Joint stiffness
  • Nervousness
  • Arthritis
  • Obsessive-compulsive disorder
  • Dizziness
  • Panic attacks
  • Streptococcal pharyngitis
  • Vomiting
  • Muscle cramps
  • Depression
  • Twitching

It is important to seek urgent medical attention should you experience signs of an allergic reaction. These can include:

  • mouth, face, tongue, throat, or lip swelling
  • difficulty breathing
  • hives
  • rash

Can You Just Stop Taking Naltrexone?

It is important that you speak to your doctor before you stop taking naltrexone. However, it is not usually the case that suddenly stopping naltrexone will cause any unwanted side effects or withdrawal symptoms.


  • The usual dose of naltrexone for the treatment of addiction to opiate drugs is between 50 and 300 mg per day.
  • Although low-dose naltrexone has been used to treat autoimmune diseases in the US since 1985, similar use in the UK and Europe is relatively new.
  • Naltrexone is one of three main drugs used in the treatment of alcoholism. The drug works by reducing the desire to drink and therefore preventing a relapse.
  • Naltrexone blocks the pleasurable effects of alcohol and stops opioid painkillers and drugs from working.
  • A typical course of naltrexone lasts for up to six months.
  • Naltrexone is rapidly absorbed and metabolised by the liver. As such, regular liver function tests are recommended.
  • Low-dose naltrexone has been used to treat conditions such as chronic fatigue syndrome, fibromyalgia, multiple sclerosis, and cancer.
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