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Glossary

abstinence - not using a particular drug; being drug-free.

opioid antagonist - a drug which blocks the effects of opioid drugs.

dependence - the drug has become central to a person’s thoughts, emotions and  activities. Stopping, or reducing the drug suddenly, can lead to physical withdrawal symptoms.

euphoria - feeling of well being - the ‘high’ or ‘rush’.

opioid - class of drugs including heroin, methadone, codeine, pethidine, morphine etc.

rapid opioid detox - this is an experimental technique to accelerate withdrawal from opioids while the person is under sedation.

receptors - nerve cells in the brain which are sensitive to particular drugs. The effects of a drug are experienced when the drug has attached itself to its corresponding receptor.

tolerance - requiring higher doses of the drug to experience the same effects.

This booklet is about the use of naltrexone to help you maintain abstinence from opioids such as heroin and methadone. It is not about the experimental use of naltrexone in rapid opioid detox.

What is naltrexone?

Naltrexone is a drug prescribed to help people maintain abstinence after they have successfully detoxified from heroin and other opioids. It does this by blocking the opioid receptors in the brain. Using heroin or other opioids while taking naltrexone is unlikely to produce any of the usual effects.

Receptors

The brain contains thousands of receptors. These are nerve cells which are sensitive to particular drugs. The effects of a drug are experienced when the drug has attached itself to its corresponding receptor.

Naltrexone is classified as an opioid antagonist because once it reaches the opioid receptor it will either push out any opioids, or if vacant, will occupy the receptor. Once it has done this it blocks any opioid entering the receptor.

Other uses of naltrexone

Naltrexone is sometimes used in the treatment of alcohol dependence. It appears to reduce the desire to drink alcohol in some people. It does not reduce the effects of alcohol, or other drugs except for opioids. 

How do you get naltrexone?

Naltrexone is only available on prescription from a doctor.

Although any doctor can prescribe naltrexone, it is recommended that you seek a doctor who is experienced in the treatment of alcohol and other drug dependence. This may include:

  • doctors who specialise in naltrexone treatment

  • doctors in clinics providing alcohol and other drug treatment services

  • general practitioners experienced in alcohol and other drug treatment.

Who can undergo naltrexone treatment?

There are a number of factors that need to be considered before a doctor can prescribe naltrexone:

  • Before starting your medication your body must be free from heroin for 7-10 days and up to 14 days if you have been using methadone. This means you must completely detox from opioids before you can begin taking naltrexone. The reason for this is that naltrexone will bring on immediate and possibly severe withdrawal symptoms if there are opioids in your body. Your doctor may decide to you with Narcan (naloxone) to ensure you are opioid free. If you do have opioids in your system, Narcan will immediately bring on withdrawal symptoms which can last approximately one hour.

  • Certain liver conditions may exclude you from taking naltrexone. These include acute hepatitis and alcoholic liver disease. Inform your doctor of any liver condition that you may have.

    Pregnant and breastfeeding women should seek the advice of their doctor. It has not been established that using naltrexone during pregnancy is completely safe.

  • There are better outcomes from naltrexone treatment for people who are highly motivated to become opioid free and who are well supported by friends and family.

What does naltrexone treatment involve?

The treatment involves taking a prescribed course of naltrexone tablets for up to one year. These tablets are taken by mouth, once a day, or every couple of days at a higher dose.

Initially your doctor may monitor your progress quite closely.

Some doctors believe that naltrexone should be taken under the supervision of a family member, pharmacist or a doctor etc.

Naltrexone is dispensed by retail or mail-order pharmacies.

As in many other conditions, the medication can be more effective when combined with counselling and ongoing support from friends and family. You should discuss this with your doctor who may be able to suggest some counselling or other support for you.  

Why undergo naltrexone treatment?

  • It acts as a disincentive to continued opioid use. Using heroin or other opioids while taking naltrexone is unlikely to produce any of the usual effects. This is because the opioid receptors have been blocked.

  • Naltrexone does not produce physical dependence.

  • It reduces the stress and anxiety about when you’ll next ‘score’.

  • As long as you no longer inject, naltrexone reduces the risk of hepatitis C, HIV and other health problems.

  • It allows you to stabilise your lifestyle.

What naltrexone doesn’t do

  • It is not a miracle cure for opioid dependence. This is why counselling and other support is important when taking naltrexone medication.

  • It does not produce any euphoric effects.

Side effects

Naltrexone is generally well tolerated in the human body. However, there have been some side effects reported. Some of these may be withdrawal symptoms associated with heroin or other opioid dependence. Symptoms may include:

  • depression

  • sleep disturbances

  • headaches

  • loss of energy

  • nausea and vomiting

  • abdominal pain

  • constipation

  • loss of appetite

  • anxiety.

Risks

The grea danger associated with naltrexone is the risk of death by opioid overdose after either skipping a dose of naltrexone or stopping naltrexone. This is because abstinence from opioids while on naltrexone rapidly reduces your tolerance to opioids.

If you take heroin or other opioids once have stopped or skipped a dose of naltrexone, you need to consider yourself as a new user. Overdose may occur if you use the same - or even a smaller - amount of heroin or other opioids that you used before taking naltrexone.

Risks while on naltrexone

  • If you have a history of depression you should let your doctor know as withdrawing from opioids can be associated with depression.

  • As naltrexone blocks the opioid receptors, taking other opioid-based treatments such as codeine-based cough medicines and pain killers will be ineffective. Any emergency service provider (ambulance officers, casualty staff etc) or doctor needs to know that you are taking naltrexone in case you need powerful analgaesia. Non-opioid treatment can be used in these situations.

Skipping doses

After each dose of naltrexone, the blocking effect wears off gradually leaving receptor sites vacant. For example, a 50mg tablet wears off between 24 and 72 hours. Higher doses may last longer. Any use of heroin or other opioids while on naltrexone is therefore risky.

If you use heroin or other opioids while on naltrexone there is a danger that these drugs are building up in the body. As the naltrexone leaves the receptor sites the site may be rushed with opioids in quantities greater than the user’s current tolerance level.

This situation is more critical when methadone is being used. This is because a dose of methadone can last in the body for 24 hours, during which time the amount of naltrexone in the body is declining. This means that a dose of methadone, which initially has no effect, may over several hours come to produce serious overdose effects.

Black market use

Using naltrexone outside the supervision of a doctor can be risky. It can lead to :

  • immediate and severe withdrawal symptoms if you are still dependent

  • overdose due to reduced tolerance if you start using opioids again once you have stopped or skipped a dose of naltrexone.

Is it the right treatment for me?

Naltrexone is one of a range of treatment options for opioid dependence. Other treatment options include:

  • methadone maintenance

  • detox, rehabilitation

  • counselling.

Deciding to undergo naltrexone requires careful consideration. The important thing to remember is that you must detox first. Naltrexone is not a euphoric alternative to heroin or other opioids. It’s a drug which blocks euphoric effects and helps you maintain abstinence.

Taking naltrexone medication is only part of the treatment. Counselling and support are valuable supplements in getting to an opioid free lifestyle.

Talk to a counsellor or your doctor to assess whether naltrexone is the best option for you.

24 hour confidential telephone counselling services

NSW
Alcohol and Drug Information Service (ADIS) - 24hr hotline
Ph: (02) 9361 8000 Toll free number: 1800 422 599

Victoria
Direct Line
Ph: (03) 9416 1818 Toll free number: 1800 136 385

Western Australia
Alcohol and Drug Information Service (ADIS) - 24hr hotline
Ph: (08) 9442 5000 Toll free number: 1800 198 024

Queensland
Alcohol and Drug Information Service (ADIS) - 24hr hotline
Ph: (07) 3236 2414 Toll free number: 1800 177 833

South Australia
Alcohol and Drug Information Service (ADIS) - 24hr hotline
Toll free number: 1300 131 340

Northern Territory
Amity Community Service
Ph: (08) 8981 8030 Toll free number: 1800 629 683

Tasmania
Alcohol and Drug Service South
Toll free number: 1800 811 994

ACT
24 hour Alcohol and Drug Help line
Ph: (02) 6205 4545

 

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