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How great a problem is heroin and other opioid use in Australia? The
lack of reliable data has hampered service planning and the
development of drug policies. Claims are made that Australia is
experiencing a heroin epidemic of unparalleled proportions, with
figures of half a million or more heroin users cited. The illegal and
covert nature of heroin use makes it difficult to quantify using
standard approaches such as general population surveys or analysis
of hospital separation data; heroin use is not revealed in a household
survey as readily as, say, an interest in Australian football or one's
favourite brand of toothpaste. But how do we measure it?
In this issue of the Journal, Hall and colleagues grapple with the quantification of heroin dependence.1 On the basis of
the number of overdose fatalities and registrations for methadone
maintenance therapy (the most common treatment for heroin
dependence in Australia), they provide estimates that are
remarkably consistent: between 67 000 and 92 000 individuals, or
about 0.7% of our population aged 15-54 years. Taking the median value
of 74 000, we may conclude that the number of heroin-dependent
individuals in Australia has doubled since the mid-1980s.
However, dependence does not equate with use, and the use of heroin,
especially intravenously, can lead to fatal overdose and
acquisition of HIV, hepatitis B and hepatitis C infection. The
proportion of heroin users who become dependent has been estimated to
be about 25% (compared with 9% for cannabis and 15% for
alcohol).2 If this assumption is
correct, the number of current heroin users in Australia would be
about 300 000. Previous work from household surveys has estimated the
total prevalence of current heroin users (both dependent and
non-dependent users) to be 0.7% of the total adult population, or
about 100 000 people.3,4 Perhaps this difference
merely reflects under-reporting, but there is still work to be done to
resolve the disparity.
There is also a substantial number of people who take prescribed
opioids inappropriately. In a related article in this issue,
Berbatis and colleagues examine trends in
prescribed opioid use,5 and show that these too have
increased in Australia over recent years. With methadone syrup (the
formulation used for maintenance treatment of heroin dependence),
this is entirely predictable. Berbatis et al found that methadone
syrup was most commonly prescribed in New South Wales, where the
greatest numbers of heroin-dependent individuals live. However,
morphine prescribing in Australia has also increased, and pethidine
use is very high by world standards. Methadone tablet prescribing was
proportionately greater in Queensland, the Northern Territory,
South Australia and Tasmania than in NSW, while morphine prescribing
was higher in the last three jurisdictions and in Western Australia.
Berbatis et al do not attempt to distinguish between appropriate
prescribing and that which is fuelling drug dependence. It is
impossible to gauge this in a study of total population use, and
determining whether prescribing is appropriate from official data
is difficult.6
An important question is whether, in some jurisdictions, methadone
tablets and morphine are being prescribed for the de facto
maintenance of drug-dependent individuals rather than for pain
relief. While there has been some prescribing of these drugs for the
treatment of dependence, differences in policy and controlled drug
legislation probably play a more important role in explaining these
variations. If significant amounts of these drugs were being
prescribed in these jurisdictions specifically to maintain
dependent opioid users, one would expect the proportion of drug users
within formal treatment programs to be substantially lower, and the
number of non-heroin opioid-related deaths to be higher, than
elsewhere. This is not the case: the proportion of heroin users
estimated to be in treatment is actually higher in those
jurisdictions where more methadone tablets and morphine are
prescribed, and non-heroin opioid-related deaths are
lower.7 The only exception is the NT,
which has not had a formal methadone maintenance program until
recently. There, medical practitioners appear to have been treating
heroin-dependent people with opioids other than methadone syrup.
What are the implications of these surveys for policy and practice?
The findings of Hall et al indicate a doubling of the number of
heroin-dependent individuals, despite a concerted campaign
against drug use since the mid-1980s. It illustrates the
difficulties in preventing an upsurge in drug use when market factors
such as low price, ready availability and a seemingly secure supply of
heroin predominate. From a medical perspective, however, we now have
effective evidence-based treatments for heroin-dependent people.
The evidence for the benefits of methadone maintenance in reducing
mortality and major morbidity (by about 75%) is now
compelling.8 Given this and the evidence
supporting the value of buprenorphine, a partial agonist, for the
maintenance treatment of heroin dependence, we should aim to recruit
and retain as many heroin-dependent users as possible in treatment in
agonist maintenance programs, for which the greatest evidence for
beneficial health outcomes exists.
There has been intense media publicity about the supposed advantages
and perils of antagonist drugs, such as naltrexone, for the treatment
for opioid dependence.9 The Commonwealth
Department of Health and Aged Care has funded a National Evaluation of
Pharmacotherapies for Opioid Dependence (NEPOD), which is trying to
dissect out the conflicting claims. Treatment with naltrexone
appears to be an option for some heroin users, but the key issue is how
the various pharmacotherapies compare in terms of mortality,
morbidity, criminal behaviour, quality of life, social
integration, economic productivity, and cost-effectiveness.
Should we countenance the wider prescribing of opioid drugs for
chronic pain when there is no clearly identified physical cause? If
the appropriate regulatory authorities monitor prescribing and
dispensing is supervised, does it matter if dependence is
perpetuated? The work of Berbatis et al does not indicate major
misprescribing of opioids. One could argue that medical prescribing
of opioid drugs, properly regulated, would both relieve suffering
and reduce "doctor shopping". It would also allow patients to
stabilise their lives and take up opportunities for treatments aimed
at abstinence when the time is right for them.
Should we be concerned about the increase in both licit and illicit
opioid use in Australia? Most certainly. In the future we may be able to
reduce demand for opioids through educational approaches,
developing our sense of community and making our society hostile -- as
best we can -- towards commercial drug dealing. Until then, we should
take pragmatic steps to treat people who have become dependent on
opioid drugs, and that entails selecting what works rather than what
feels good.
John B Saunders
Professor of Alcohol and Drug Studies
Department of Psychiatry,
University of Queensland, and Director
Alcohol and Drug Services of
the Royal Brisbane and
The Prince Charles Hospital Health Service
Districts
Queensland Health, Brisbane, QLD
Alun H Richards
Manager, Drugs of Dependence Unit
Queensland Health, Coorparoo DC,
QLD
- Hall WD, Ross JE, Lynskey MT, et al. How many dependent heroin users
are there in Australia? Med J Aust 2000; 173: 528-531.
-
Anthony JC, Warner LA, Kessler RC. Comparative epidemiology of
dependence on tobacco, alcohol, controlled substances and
inhalants: basic findings from the National Comorbidity Survey.
Exp Clin Psychopharmacol 1994; 2: 244-268.
-
Australian Institute of Health and Welfare. 1998 National Drug
Strategy Household Survey: First Results. Canberra:
Australian Institute of Health and Welfare, 1999.
-
Maxwell JC. Drug use in Australia and the United States: a
comparison of the 1995 and 1998 national household surveys in both
countries. Drug Alc Review. In press.
-
Berbatis CG, Sunderland VB, Bulsara M, Lintzeris N. Trends in licit
opioid use in Australia, 1984-1998: compararative analysis of
international and jurisdictional data. Med J Aust 2000; 173:
524-527.
-
Richards AH. The use of controlled-release morphine sulphate (MS
Contin) in Queensland, 1990-1993. Med J Aust 1995; 163:
181-182.
-
Hall W, Ross J, Lynskey M, et al. How many dependent opioid users are
there in Australia? NDARC Monograph No. 44. Sydney: National Drug and
Alcohol Research Centre, 2000.
-
Caplehorn JRM, Dalton MSYN, Halder F, et al. Methadone maintenance
and addicts' risk of fatal heroin overdose. Subst Use Misuse
1996; 31: 177-196.
-
Hall W, Mattick RP, Saunders JB, Wodak A. Rapid opiate
detoxification treatment. Drug Alc Review 1997; 16:
325-327.
©MJA 2000
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