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ANTA Alcohol & Other
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Further information about the effects and
treatments for different drugs
Naltrexone
Naltrexone has recently become available in Australia as a tablet for use in relapse
prevention. Naltrexone is an opiate ‘antagonist’, meaning it antagonises, or blocks the effects
of opiates. It works by attaching itself to parts of tissues, called receptor sites, normally
affected by opiates. However, naltrexone has no opiate-like effects. Compare this to heroin
which attaches to the same sites but causes a multitude of effects – euphoria, drowsiness,
constipation, etc. The individual taking naltrexone will not feel any pleasure from the drug,
but it will block any heroin from getting into the tissues.
To use an analogy, think of an office with a number of computer workstations. If active
workers occupy the seats of these workstations, there is a result. Work gets done as they
punch away at keys on their terminals. These workers are like heroin at tissue (receptor)
sites. Now, imagine that these workers seats were taken by people who did nothing. These
slackers are like naltrexone molecules, blocking the active agents from affecting the tissue.
The primary aim of naltrexone treatment is relapse prevention, to discourage the heroin user
from using.
Naltrexone works in a similar way with alcohol dependency. The alcoholic taking naltrexone
will not get an effect from alcohol, and is therefore less inclined to start drinking again.
Phlebitis
Illicit (and some licit) drugs may be particularly irritating to veins. When injected into limb
veins, irritation or infection (phlebitis), or scarring/clotting in the veins may occur
(thrombophlebitis). This has been of particular problem with some drug users who inject
certain preparations of the sedative temazepam.
Endocarditis or subacute bacterial endocarditis
Injecting drug use is a risk factor for infection of the valves of the heart (endocarditis). This
occurs when a small amount of bacteria is pushed into the bloodstream with a needle.
Endocarditis usually requires long term treatment with high dose antibiotics, and may be
fatal. It is minimised by the swabbing the site of injection with alcohol prior to injecting (these
swabs are distributed by NSEPs or NSPs).
© ANTA 2000
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ANTA Alcohol & Other
Drugs Toolbox
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Methadone
Methadone is an opioid (synthetic opiate) that was discovered over 50 years ago. For much
of the last 40 years has been the mainstay of treatment of opiate dependence. This form of
treatment is sometimes termed substitution, as it involves substituting a safer and more
manageable drug for heroin.
Methadone has a long half-life, meaning it stays in the body for a long time. To illustrate this,
it is useful to compare half-lives of heroin and methadone. Heroin has a half-life of a few
hours, meaning that a user must periodically ‘top up’ to maintain the desired effect.
Methadone’s half-life is in the vicinity of 1-2 days, meaning that a single dose will usually last
until the following day.
In Australia the prescription of methadone to opiate dependent persons is tightly regulated,
and these regulations may vary between States and Territories. For example, at time of
writing the Northern Territory had no provision within its health or drugs and poisons acts to
allow for the supply of methadone to treat opiate dependence.
Methadone is not appropriate for all heroin users. It is usually offered as a treatment option to
long term users who can make an informed choice about whether they are willing to
undertake this form of treatment. In most parts of Australia, there are GPs and clinics that
can prescribe and monitor methadone therapy.
For a drug user involved in crime, at risk of overdose or blood borne virus infection or is
experiencing major life disruption due to heroin, methadone can be an enormous help. When
a user is stabilised on methadone, craving for heroin is usually substantially reduced. Use of
heroin while taking methadone often does not produce the same euphoria and is not as
appealing. A heroin user can pick up methadone at a pharmacist each day and is monitored
by treatment services, helping to restore some normality and routine.
The downside of methadone is that it is a long term treatment, usually a year or more. It is
difficult for the individual to travel with the requirements for daily dosing. Side effects include
dysphoria (low mood), increased sweating, loss of sex drive, puffiness in extremities,
constipation and insomnia. These do not occur in everyone and are managed by dosage
modifications. The methadone patient risks overdose if other drugs, including heroin or
benzodiazepines, are used on top of methadone.
© ANTA 2000
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ANTA Alcohol & Other
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There are some misconceptions surrounding methadone worth addressing:
Methadone rots your teeth.
Opiates, including heroin, reduce
saliva which increases the risk of
dental caries. People on methadone
are educated about dental hygiene
and encouraged to chew sugar free
gum.
Methadone makes you fat.
While fluid retention may occur with
methadone, the main reason people
put on weight on methadone is
probably because their appetite is
restored. The commencement of a
methadone program is a good time
for educating individuals about
healthy diet.
Methadone leaches the calcium out
of your bones/gets into the bones.
There is no evidence that this
occurs.
Methadone is harder to withdraw
from than heroin.
There is no doubt that the
withdrawal symptoms from
methadone are more protracted
than heroin, probably because its
half-life is longer. Withdrawal from
heroin may take in the order of 1-2
weeks, whereas withdrawal
symptoms from methadone may
take over 6 weeks. However, this is
managed by very slow reduction in
dose.
© ANTA 2000
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ANTA Alcohol & Other
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Blood borne diseases (Blood borne viruses or BBVs)
People who inject drugs (particularly heroin and amphetamine) are at particular risk of blood
borne viruses. The major BBVs of relevance to injecting drug users are the following.



Hepatitis B

transmitted by blood, body fluids; sexually transmitted

characterised by a severe acute illness which usually resolves completely

a small percentage of infected individuals develop a chronic carrier state, and
these individuals may progress to chronic liver disease and liver cancer

injecting drug users (IDUs) should be strongly encouraged to undertake
Hepatitis B vaccination.
Hepatitis C

transmitted by blood

sexual transmission may occur, but this is uncertain

high prevalence of infection in Australian IDUs

most infections progress to a chronic, low grade hepatitis; over several
decades Hepatitis C may progress to cirrhosis or liver cancer

no vaccine is available

treatment with a drug called interferon, with or without the addition of another
agent (ribavirin) is available but is only partially effective.
Human Immunodeficiency Virus (HIV)

characterised by a variable period of incubation, often progressing to a severe
immune deficiency illness (AIDS)

blood and body fluid transmission; sexually transmitted

incidence and prevalence in Australian IDUs is low

drug dependent individuals may be at risk of sexually transmitted HIV (and
other sexually communicable infections) due to impaired judgement, lifestyle
or sex work
information about safe sex and injecting, availability of barrier contraceptives
(condoms, dental dams) and clean injection equipment are essential in
reducing HIV related harm

Management of injecting drug use should include counselling, testing, vaccination and
management of BBVs. The risk of transmission of blood borne diseases is minimised by the
use of clean injection equipment such as provided by needle and syringe exchange services.
© ANTA 2000
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