David Moore, School of Health Sciences, Deakin University, and Paul Dietze, Turning Point Alcohol & Drug Centre and School of Health Sciences, Deakin University

Summarising the findings of past Australian research on overdose, we can make several points. First, that risk factors for overdose in general include: mixing heroin with benzodiazepines and/or alcohol; being out of drug treatment; and using the drug under conditions of changed tolerance, (e.g. resuming drug use following a period of abstinence or increasing use following a reduction in use). Additional risks for heroin-related death include using heroin by oneself and failing to call for assistance with an overdose for fear of arrest or because of lack of knowledge. We can also note that the 'typical' overdose victim is not a novice but an experienced, male heroin user not in treatment at the time of death; that overdose deaths are only moderately related to fluctuations in purity; that overdose is also possible via smoking, snorting and swallowing heroin; and that 'instantaneous' overdose deaths represent only a minority of overdose cases (i.e. most deaths occur some time after the use of the drug).

Based on this research, a number of strategies for the prevention of overdose have been recommended: public and peer-based education and health promotion to reduce the risks outlined above (i.e. sample heroin first, don't mix with other drugs, don't inject alone, always call an ambulance in the event of overdose, monitor one's tolerance); expanded treatment services; a trial of naloxone provision to heroin users for peer administration; greater regulation of benzodiazepines; a trial of safe injecting facilities; overdose-specific support, recovery and referral services; court diversion into treatment; law enforcement that does not increase drug-related harm; and CPR training for drug users. These are all worthwhile prevention strategies. However, they do not address many significant issues identified during recent research on street-based injecting drug use (IDU), street sex work and service provision in the St Kilda area of Melbourne.

Most of the people in the study reported overdose experiences relating to the five behavioural risk factors outlined above, yet many of them were also well aware of prevention messages around polydrug use, and, to a lesser extent, injecting with other people present and resuming use following abstinence. Given this apparently high level of awareness of risk factors for overdose, the question we should now be seeking to answer is: Why do so many people continue to engage in 'risky' practices? To begin to explain this, we need to understand the contexts of 'risk'.

The St Kilda materials contain several useful illustrations. Many of the women in the study are involved in street sex work, an extremely hazardous occupation with a high probability of physical and/or sexual assault, robbery, arrest and sexually transmitted infection. Some of these women and many of the men are also involved in various forms of criminal 'rorts' and in unstable accommodation. In this context, messages about overdose prevention are added to a long list of 'possible risks' encountered during the course of a typical day. This is not to say that street-based IDUs and sex workers are unconcerned about their health but that, seen in context, there are many other, more pressing, priorities that must also be met, e.g. avoiding arrest and assault, evaluating potential clients for safety, finding the money to buy and use drugs, avoiding creditors and finding somewhere to live.

Polydrug use is often unplanned, resulting from days that lack routine (except for obtaining money and heroin on a regular basis), the search for action and purpose, or mistakes. Because of the relatively low cost of benzodiazepines and highly alcoholic drinks, many study participants had consumed several units of one or both before unexpectedly having the opportunity to inject heroin, which they then took.

Another clear finding from the research is that categories such as 'IDU' and 'overdose' do not allow for the variety of cultures and practices within the IDU population, even at the local level of St Kilda. For example, people's accounts of overdose, and of heroin use more generally, often include descriptions of a 'honeymoon' period during the early stages of use. A feature of the honeymoon period is 'getting smashed' (i.e. being heavily intoxicated) - tolerance is low, the cost is affordable, and the drug's effects are powerful and intensely pleasurable. With the age of first use of heroin falling in recent years, we can also assume that this honeymoon period usually corresponds with the mid/late-teens or the early twenties, stages of life when many demands are placed on young people.

If 'getting smashed' is the main aim of using, for whatever reason (e.g. coping with family problems, joining a peer group of heavy users), strategies for reducing the amount of heroin used, and therefore the risk of overdose, are less likely to be adopted. Many people involved in street-based drug and sex work markets also have accompanying problems of homelessness, mental illness and acute poverty, and an associated desire for extreme intoxication; they may therefore see messages about testing heroin strength to prevent overdose as irrelevant.

There also appear to be differences in male and female experiences of overdose. Women more often describe situations where part of their role appears to be to regulate their partners' heroin use, especially after periods of abstinence, in order to prevent overdose. Men are sometimes involved in overdoses through providing too much heroin to their partners. While some women take, or are forced to take, passive roles in managing money, scoring drugs, and preparing them for injection (even some who are the main income earners through street sex work), some men also accept a passive role in situations where their health may be at risk. For example, one young man, with a history of sexual abuse, schizophrenia, suicide attempts and institutional care, calmly described how he took no role in the purchase and preparation of the heroin that was then injected into him by a newly-made friend. In a street drug market such as St Kilda, where 'friendship' is relatively rare and networks change rapidly over time, he trusted his accomplice to provide the 'right' dose to produce intoxication but not overdose.

The question of 'friendship' is related to the social organisation of the drug market. Large segments of the St Kilda drug-using population share little apart from their common participation in street-based IDU and sex work. The transience of people, networks and lifestyle means they are less likely to inject in a private setting and more likely to do so in a public place, where there is increased risk of harm. Likewise, 'never-use-alone' advice ignores the difficulty in street drug markets of finding someone to trust without being 'ripped off'. One exchange witnessed during the research featured a female sex worker urging a female associate not to inject heroin alone in a nearby park. The sex worker suggested that she take her (i.e. the sex worker's) boyfriend with her to be safe. The would-be park injector looked a little hesitant. The sex worker assured her that the boyfriend would not expect a 'shot [injection of heroin]' in return for his company and that she (and her money and drugs) would be quite safe with him. Overdose prevention needs to be aware of these social factors that might undermine attempts at peer education and community development amongst IDUs.

Prevention messages also need to recognise the different kinds and levels of resources available to different groups of IDUs. Middle-class, privately educated, tertiary-qualified IDUs are more likely to have family, work and social networks and financial resources to draw on in organising their drug use and in coping with related problems. Street-based IDUs (some of whom are also from middle-class backgrounds but who have exhausted these resources) do make 'choices' about their drug use, but these 'choices' are much more limited.

There are many starting points in these data for designing individual behaviour change and peer education programs targeting particular aspects of IDU and overdose. However, the effectiveness of well-intentioned but individually-focused peer education and community development programs is likely to be limited unless they take account of the stages in drug careers, variation in IDU cultures (e.g. based on gender, social class, stage of drug career), reasons for use and broader aspects of risk environments (e.g. the unavailability of overnight NSPs in St Kilda leading to risky IDU). Reducing overdose, and drug-related harm more generally, requires a range of approaches that, working together, take account of all levels - from the individual through to the environmental.