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Naltrexone Treatments

What is Naltrexone?

Naltrexone, an opioid antagonist, is a safe and effective medication. Its blocking mechanism means that heroin, methadone (Physeptone) and all other opiates such as morphine, codeine, DF118 and Temgesic will no longer produce their desired effects like the intense feeling of pain relief and euphoria, effectively reducing the desire to take these drugs.

How does it work?

Naltrexone enters the brain and nervous system and attaches itself to small areas called receptor sites. For heroin to produce its effects, it must attach to the same receptors, but Naltrexone blocks it for reaching them for up to three days after an oral dose. These receptors are part of the complex reward mechanisms that motivate us and lead to repetitive behaviour. If the reward is blocked, the craving and dependence reduces and new behaviours establish over time. It works well for relapse prevention in opiate addiction and often, but less predictably, in alcohol dependence.


Why consider Naltrexone?

The OAD Clinic offers naltrexone treatments to prevent opiate relapse. The medication should be taken after the body has been fully detoxified from opiates, otherwise strong withdrawal symptoms may be experienced. It is part of our comprehensive opiate addiction treatment programme that includes counselling, monitoring and lifestyle changes.

Learn more about our drug treatment programmes.


Naltrexone can also be effectively used in alcohol treatment programmes. It blocks opioid receptors responsible for the euphoric effects of alcohol mediated by endorphins (brain reward system), reducing the desire to drink. Naltrexone works best as part of a treatment programme that includes psychosocial support such as counselling and therapy.

Learn more about our alcohol treatment programmes.

Naltrexone Formulations

Naltrexone is available in three forms:

Naltrexone Implants

A Naltrexone Implant is a specially formulated, sterilised preparation for insertion under the skin during a 20-30 minute minor surgical procedure. Its effects last up to 6 months. Naltrexone Implants do not have a product licence in the UK and are still regarded as experimental.

Learn more about Naltrexone Implants


These are usually swallowed daily and it is best that consumption is supervised. If not taken for a couple of days, relapse to opiate use is possible. They do have a product licence.

Depot Injections

This is a liquid preparation of Naltrexone for injection into deep muscle, slowly released over approximately one month. The advantage of this formulation is that no surgical procedure is needed, with no visible lump or scar. Compared to Implants, the disadvantage is its shorter duration, requiring more commitment from the patient to have it repeated monthly, without relapsing in between.

Currently, this formulation does not have a product licence in the UK.

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