"reducing alcohol and drug related harm in our communities"
Key Information



Naltraxone (Buprenorphine, Lofexidine, Britoflex, Subutex)


17-(cyclopropylmethyl)-alpha-(1,1-dimethylethyl)-4,5-epoxy- 18,19-dihydro-3-hydroxy-6-methoxy-alpha-methyl-6,14- ethenomorphinan-7-methanol


Bupe, subs, subbies, orange guys


These are a semi-synthetic opiate (the term opiate describes any of the narcotic opioid alkaloids found as natural products in the opium poppy plant).  If you stop taking heroin, they can prevent or reduce the unpleasant withdrawal symptoms. Many people stay on them long-term, but some people gradually reduce the dose and come off drugs altogether. You should not take any street drugs or much alcohol when you are taking these.  If you take these, you are unlikely to get withdrawal symptoms if you stop heroin (or the withdrawal symptoms are much less severe).


These are a tablet which you put under the tongue. The tablet dissolves over 3-7 minutes and is absorbed straight into the bloodstream from the mouth. (The tablets do not work if you swallow them into the stomach).   Because of its opioid agonist effects, these opiates are abusable, particularly by individuals who are not physically addicted to opioids

HEALTH RISKS (long term) which includes withdrawal & tolerance:

These are an opioid partial agonist. This means that, although these are opioids, and thus can produce typical opioid agonist effects and side effects such as euphoria and respiratory depression, its maximal effects are less than those of full agonists like heroin and methadone. At low doses they produce sufficient agonist effect to enable opioid-addicted individuals to discontinue the misuse of opioids without experiencing withdrawal symptoms. The agonist effects can increase linearly with increasing doses of the drug until at moderate doses they reach a plateau and no longer continue to increase with further increases in dose—the “ceiling effect.” Thus, these carry a lower risk of abuse, addiction, and side effects compared to full opioid agonists. In fact, in high doses and under certain circumstances,  these can actually block the effects of full opioid agonists and can precipitate withdrawal symptoms if administered to an opioid-addicted individual while a full agonist is in the bloodstream.


Many GPs will refer users to a community drug team to be assessed. Following assessment, the community drug team may prescribe these. Some GPs work in a 'shared care' arrangement and will prescribe whatever is recommended by a community drug team. Some GPs who are specially trained may assess and prescribe these without the need for referral.

  1. The main use of Naltrexone is for the treatment of alcohol dependence.
  2. For people who have stopped drinking, Naltrexone reduces the craving for alcohol which many alcohol dependent people experience when they quit drinking.
  3. Naltrexone works by blocking the effects of drugs like Heroin and Cocaine in the brain. As an Opioid receptor antagonist, Naltrexone simply blocks the normal reaction of the part of the brain that produces the feeling of pleasure when Opioids are taken.
  4. Because Naltrexone blocks the effects of Opioids, it is sometimes prescribed for 12 months for those trying to manage drug dependence.
  5. The benefits of this drug are apparently due to the temporary inhibition of Endorphins (a natural pain-killer, produced in the brain).
  6. Naltrexone does not help someone stop drinking or doing drugs, it is used to help people who have already stopped maintain abstinence.
  7. Naltrexone helps patients overcome urges to abuse opiates by blocking the drugs’ euphoric effects
  8. Naltrexone itself was approved in the 1980’s for the purpose of helping Heroin or Opium addicts, by blocking the effect of such drugs. By blocking Opioid receptors, Naltrexone also blocks the reception of the Opioid hormones that our brain and adrenal glands produce.
  9. Since the mid-1980's, Naltrexone has consistently demonstrated a markedly beneficial effect in the treatment of HIV/AIDS.
  10. Naltrexone may cause liver damage when taken in large doses. It is not likely that Naltrexone will cause liver damage when taken in recommended doses
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