Estimating the proportion of prescription opioids that is consumed by people who inject drugs in Australia
Degenhardt, L and Gilmour, S and Shand, F and Bruno, R and Campbell, G and Mattick, RP and Larance, B and Hall, W, Estimating the proportion of prescription opioids that is consumed by people who inject drugs in Australia, Drug and Alcohol Review, 32, (5) pp. 468-474. ISSN 0959-5236 (2013) [Refereed Article]
Copyright 2013 Australasian Professional Society on Alcohol and other Drugs
Introduction and aims: To estimate the contribution that people who inject drugs (PWID) make
to population-level use of prescription opioids in Australia.
Design and methods: Data on prescriptions of oxycodone, morphine and methadone tablets
were obtained for New South Wales, Victoria, Tasmania, and Queensland, and time series
analyses used to characterise the trends from 2002-2010. Estimates of the number of PWID
were combined with data on their levels, frequency and typical doses of morphine, methadone
tablet (only prescribed in Australia for pain) and oxycodone from 2004 to 2010. Estimated
consumption per 1,000 PWID and per 1,000 persons 20-69 years were contrasted; and the
proportion of total consumption accounted for by PWID estimated.
Results: Morphine prescribing declined; oxycodone prescribing increased. PWID had far higher
rates of prescription opioid consumption (DDDs per 1,000) than the general population.
Tasmania had highest use of prescribed opioids. PWID contribution to morphine consumption
in Tasmania increased to 28% (range 22-37%) in 2010; elsewhere, PWID contribution was lower
(midpoints of 2-12%, 2010). Methadone tablet use was less elevated compared to the general
population. With the exception of Tasmania, PWID were estimated to consume less than 5% of
Discussion and conclusions: PWID use prescription opioids at high levels and can account for a
significant proportion of consumption. Increased oxycodone prescribing in Australia has not
been driven by PWID. Opioid substitution therapy and other effective treatments need to be
more available and attractive to PWID.