NALTREXONE

FACE TO FACE IN THE NALTREXONE ZONE

ISSUE2

As you may know from our first issue, our Science on Substances feature is going to try to keep you informed about the variety of drugs that are currently involved in research trials around the world. Drugs used for detox, maintenance and abstinence, drugs that get you stoned and drugs used for your health and wellbeing, we'll try and explain them all. This issue we introduce naltrexone....

There has been quite a lot of interest in naltrexone, not just in the UK but around the world. However, it is not just a single treatment option. There are various ways of using naltrexone - as part of a 'rapid' detox and as a daily dose to maintain abstinence. So, this issue we thought we should introduce naltrexone - its origins, its uses and its future.

What is Naltrexone and How Does it Work?

For heroin, (and other opiates such as methadone, morphine, palfium, codeine etc), to produce their effects - and get you stoned - they need to be able to attach themselves to small areas in the brain and nervous system called receptor sites. Naltrexone not only blocks these receptor sites, which prevents any opiates from working, but also displaces or removes any existing opiates that currently occupy those sites. Such drugs are called 'opiate antagonists' - they antagonise (to put it mildly!) any opiate. This means that if you take naltrexone when you have an opiate 'habit', you will find yourself withdrawing quickly and intensely as the opiates are rapidly (rather than slowly) removed from your receptor sites, and your body reacts to their absence. However, if you've already detoxed, taking naltrexone may help keep you abstinent as using heroin simply will not work. Naltrexone is sometimes referred to as a 'non-drug' because it doesn't really have any effect other than blocking the effects of opiates. Naltrexone is long lasting - from 24 to 72 hours depending on the dose, and it comes as a tablet, or as an implant. It is closely related to Naloxone (or Narcan), the 'pure' opiate antagonist which doctors use for opiate overdoses; but naloxone only works when injected and lasts for only a short time - less than an hour.

The Origins of Naltrexone

Naltrexone is a relatively new drug in the UK, becoming available in 1985 and receiving its product license in 1988. However, it has been used in the US since the early 70's when Nassau County Jail (Long Island) initiated the Narcotic Antagonist Jail Work Release Program. Non-violent prisoners with a history of opiate misuse were allowed out during the day to attend work/training courses as long as they were administered naltrexone regularly (in tablet form). Unfortunately, as addicts were relegated to the bottom of the jails 'trust ladder' this was the only way these prisoners (the majority in Nassau County Jail) would ever have been admitted to this type of programme. The use of Naltrexone was pioneered in this country by Dr. Colin Brewer at the Stapleford Centre. Drawing on American experiences, he used it along with 'strong sedation' to provide users with greatly accelerated detoxes that were over in 48 - 72 hours and felt less unpleasant than traditional 14 - 21 days reducing methadone regimes. Doctors at the University of Vienna in Austria then developed the Ultra Rapid Detox technique using naltrexone with a short general anesthesia so that patients were unconscious for most of the detox. Details of this technique were first published in 1988. Dr Brewer further developed the technique resulting in a compromise between the Ultra Rapid and Rapid detox by using naltrexone and 'strong sedation' to provide users with greatly accelerated withdrawals without the added expense and intensive nursing that was required using anesthesia. The idea behind naltrexone is that if an opiate user can stay 'clean' for some time, then it is easier for people to learn to change their drug-using behaviour patterns. If heroin no longer 'works' then the user will stop scoring and stop hanging around drug using and places friends. But naltrexone has its detractors. Freudian types and others, who believe that people use drugs because of personal and emotional problems, say that naltrexone will do nothing to confront or deal with such issues. However, it is now thought by many that the problems many drug users have are a result of their addiction and not the cause. Therefore, if a person can be kept straight for a while, many of their 'problems' may disappear. However, it is worth remembering that naltrexone only works for opiates and not other drugs such as amphetamines, barbiturates or cocaine.

Naltrexone and its Uses

Naltrexone tablets - 50 mg tablets taken daily. Of course, it only works as long as you take it - which is why clinics stress the importance of having someone to supervise the taking of the tablets. Naltrexone tablets are available on the NHS and can be prescribed by any doctor.

Advantages - Easily available and relatively cheap.

Disadvantages - Only work if you take them.

Naltrexone Implant - inserted after any detox to maintain abstinence. A one inch incision is made under local anaesthetic in the lower abdomen or the back of upper arm. They are about 1.4cm in diameter and approx 9mm thick. Effects last from 6 - 12 weeks, and then patients need the implant renewed.

Advantages - You can't forget to take it, which makes relapse on opiates practically impossible, (good for those who don't have someone to support them).

Disadvantages - minor surgery and a small scar, occasional infection/inflammation at site, four times more expensive than tablets and not currently available on the NHS. Naltrexone implants have not been produced by a major drug company and should still be regarded as experimental. COST only available privately - approx £ 370 for outpatient insertion).

Rapid Opiate Detox Under General Anaesthesia - Premedication is prescribed 12 hours before the procedure starts. After further premedication with anti-withdrawal drugs and sedatives, naloxone is used by injection to detach the opiates from the receptors in the brain - speeding up the withdrawal process. Instead of taking 2-5 days for withdrawals to peak, the worst of the symptoms are over in a few hours. During this acute phase, patients are fully anaesthetised in an intensive care unit for 4-6 hours, then kept sleeping for up to 14 hours. Many patients can return home the following day (with supervision) whilst some may need a second day of nursing. Doesn't completely eliminate withdrawals but once you are awake, you start to feel better rather than worse. Out-patient follow-up is usually included.

Advantages - relatively humane and more comfortable than other methods, quickest return to work, naltrexone implants can also be inserted whilst anaesthetized.

Disadvantages - always inherent risk with general anaesthetic, some users awake still feeling sick, but these symptoms do get better. Procedure is expensive, potentially risky for those people with bad health problems.

COST: £ 3700, a bit more if you are receiving the implant as well.

Rapid Opiate Detox Under Sedation With this method you are in hospital for about 5 days. If you're on methadone, you may be required to transfer to morphine or other opiates a week beforehand. After admission you are given generous amounts (depends on your interpretation of generous!) of sedatives and anti withdrawal drugs. After 3-4 days naltrexone is started and rapid withdrawals commence. Aftercare included.

Advantages - no anaesthetic so lower risk to patient, most people have little recall of event, it's a lot cheaper than general anaesthetic.

Disadvantages -over sedation is avoided so it may not always control withdrawals - this causes some patients to leave without completion. At least a week is needed off work and there is some discomfort.

COST: about £2250
A version of this technique can also be done at home, with clinics providing a nurse, or (cheapest of all) a friend to act as carer and supervise the person whilst they are sedated. This way it is much less expensive. COST £ 150 - £ 1250 depending on the facilities used.

Some medical insurance companies may cover the cost of inpatient treatments and implants and local NHS health authorities are sometimes willing to pay for them.

Many NHS GP's also prescribe naltrexone tablets to aid abstinence (check out subutex for a half way version - see Subutex on our Science on Substances webpage)

Naltrexone and it's future

Naltrexone is used in many countries such as Australia, America and Israel and is still undergoing research and trials. While it may help those who are really determined to stop using, it is always important to realise that the battle is only half fought by naltrexone. As previously stated, if you're on methadone it is better to transfer to another opiate before detoxing because methadone can make withdrawals more difficult, certainly they will take longer. Fears have also been raised about pain relief options while on naltrexone treatment. The bottom line is, that if you are in a serious car accident etc and need some immediate pain relief, you will have to wait approx 3 days to a week before you could feel any opiate based pain killer such as morphine. In the meantime you would have to make do with non opioid analgesics (ketamine, nitrous oxide etc) which are known to be weaker than opiate based drugs in terms of pain relieving capabilities. This can and has endangered lives. Naltrexone's side effects are said to be very mild. You don't experience any withdrawal symptoms when you stop taking it. Adverse reactions such as; difficulty sleeping, anxiety, abdominal pain, nausea and headaches and some reports of severe depression - have been reported but might not necessarily be caused by the medication, they could be related to post detox blues…But depression has been cited a lot by our peers certainly - and from a medical point of view its quite likely that because of the way it affect endorphins, depression is very likely. Make sure you have loved ones around whenever possible.

More information available from Dr C Brewer of the Stapleford Centre 0171 823 6840. References ; NUAA NEWS Vol 25,27 (1998), Stapleford Centre, Brewer, C. (ed) (1993) 'Treatment Options In Addiction; Medical Management of Alcohol and Opiate Abuse' The Royal College of Psychiatrists, Gaskell, London SW1

Written 2000 Click here to return back to SOS