There are two similar
chemical substances: Naltrexone and Naloxone. Both are generic names, the names
of the chemical substance with some effects on human body and brain. In this
paper I only will concentrate on one of both drugs, namely
Naltrexone.
The drug is
41 years old, has appeared
in the
published clinical literature for over thirty years, and more than 1700
references to
it are to be
found in the Medline database. It is sold under the trade names Nabilon,
Nalorex, Nemexine, Narcan. These
denominations vary from
country to country.
How it
works
Naltrexone blocks the
opioid receptors in the brain for 24 hours. The desired effect of injected or
smoked heroine is not achieved. The consequence is that persons under the
influence of Naloxone consuming opioids like heroine, morphine or codeine
experience no drug effect, no high.
Therefore drug addicts
begin to realise the futility of consuming opiates and learn to cope without the
'helping effects' of opiates. They learn to live, to feel, to react, to work
without being under any drug influence. This
is what differentiates it from all other substitute drugs. If addicts
have a relapse, they will not suffer any effect of the injected drug. Naltrexone
has no subjective effects or potential for abuse and
addiction.
Naltrexone was originally
used to treat dependence on opioid drugs but has recently been approved by the
FDA as treatment for alcoholism for a variety of reasons. Firstly, Naltrexone
can reduce craving, which is the urge or desire to drink. Secondly, Naltrexone
helps patients remain abstinent. Thirdly, Naltrexone can interfere with the
tendency to want to drink more if a recovering patient slips and has a
drink.
Dosage
Naltrexone is taken orally
or implanted under the skin. Drug addicts begin treatment after a successful
medical detoxification in a residential setting. In order to prevent
precipitating an opiate abstinence syndrome, individuals must be medically
detoxified and opiate free for several days before Naltrexone can be taken. The
drug is taken daily or three times a week: Monday and Wednesday 100mg, Friday
150 mg. Implants in the skin are usually effective for six-week
periods.
Revival Drug Narcan
(Naloxone)
Naloxone is
the revival drug given to people in Emergency Rooms and Ambulances when they
show symptoms of overdose. Patients immediately display withdrawal symptoms
because of the blockade of the opioid receptors. This sudden sobriety, the
sudden unpleasant feeling so called cold turkey', often makes the patient/user
very violent and they often leave the Casualty Room or scene of overdose and go
back to using opiates in a matter of a few hours - or as long as it takes them
to get some more drug.
Side effects
Naltrexone
has virtually no significant drug interactions - other than with opiates - and
combines well with the other non-opiates that our patients have to
take.
In the
largest study, the most common side effect of Naltrexone affected only a small
minority of people and included the following: nausea (10%), headache (7%),
dizziness (4%), fatigue (4%), insomnia (3%), anxiety (2%), and sleepiness (2%).
These side effects were usually mild and of short duration. One serious drawback is that Naltrexone can have toxic effects
on the liver. Blood tests of liver function are performed prior to the onset of
treatment and periodically during treatment to determine whether Naltrexone
should be started or discontinued if the relatively rare side effect of liver
toxicity is taking place.
As in
treatment for alcoholism, Naltrexone's side effects, predominantly nausea, have
been severe enough to discontinue the medication in 5-10 % of the patients
starting it. For most other patients, side effects are mild or of brief
duration.
Naltrexone should not be
used by pregnant women, individuals with severe liver or kidney damage or by
patients who cannot achieve abstinence for at least 5 days prior to initiating
medications.
Disadvantages of
Naltrexone Treatment
As drug
addicts remain in the social environment where they used to
take drugs, it could
be very difficult for them to distance themselves from other drug users and the
drug scene. Therefore, they need intensive psychological help or psychotherapy
during the time of recovery, further counselling and social support, employment
and legal assistance.
For those
who are still young and lack self-discipline
- or who are tempted by their life circumstances to take "street
drugs", Naltrexone is not the optimal treatment. The risk is that
addicts who mostly take several drugs continue to take other drugs like cocaine,
amphetamine, ecstasy or marihuana.
Australia's leading
research with Naltrexone implant treatment
For
many years now there have been outpatient facilities in Australia which
distribute Naltrexone to drug addicts. The results achieved are remarkable.
Naltrexone
has been administered in the form of tablets. A great problem has always been that a percentage of addicts
left the treatment programme in the first months. These addicts who wanted to
take heroine again, stop taking it under different purposes i.e. headache or
nausea, so they had to stop taking Naltrexone. In this time the effect of
Naloxone diminished and when they inject heroine, they had the desired effect of
a high. So to implant Naloxone
could be a good alternative, if the addict has no considerable side effects.
Australia is at the
leading edge of world practice in Naltrexone implants. The National Health and
Medical Research Council are currently funding a clinical trial to compare oral
and implant Naltrexone treatment. Naloxone has a huge potential for treatment of
heroin addiction both in Australia and world-wide. We need everyone to work
together to pool all our efforts, resources and experience to examine positive
options such as whether Naloxone implants might be a
tool to be used to move the treatment in the direction of getting addicts
off drugs.
Recommendations
of the NIDA:
Proposals made to enhance
the effectiveness and expand the use of Naltrexone in treating heroin addiction
included the following:
- In order to
achieve an opioid free state required to start Naltrexone, the detoxification
procedure needs to be tailored to assist transition to Naltrexone treatment.
- To improve
medication compliance: Develop long acting delivery system, such as depot
formulation of Naltrexone which lasts for up to 30 days to minimize patient
decision making; co administer Naltrexone with SSRIs or other antidepressant;
add special motivation enhancing behavioural or psychosocial adjuncts.
- To expand the
use of Naltrexone in treatment: Use in special patient populations with high
external motivation to remain drug free such as impaired professionals,
drug-experimenting adolescents, parolees, probationers, work-release
participants. etc.
- To improve
the treatment effectiveness of Naltrexone: Educate and train treatment
practioners the correct and effective way of using Naltrexone in treating
opioids addicted patients.
Scientific and Advisory
Board, Eurad
