Breaking the deadlock over an Australian trial of injectable opioid maintenance

Injectable heroin maintenance has been advocated as a form of treatment for opioid dependence that would attract, and retain in treatment, addicts who have either not sought treatment or who have failed at other forms of treatment, including methadone maintenance. Advocates of heroin maintenance argue that it would increase the proportion of addicts in treatment and reduce heroin use, drug-related crime, and deaths due to overdose.1

A 1991 proposal by a Select Committee on HIV, Illegal Drugs and Prostitution of the ACT Legislative Assembly led to a feasibility study for a heroin trial in the ACT.1 In 1997, the Ministerial Council on Drug Strategy voted in favour of a heroin trial, but the trial did not proceed, as the Federal Government would not amend legislation to allow heroin to be imported for the trial or allocate funds to monitor the use of heroin in accordance with international treaties.2

Dramatic rises in deaths caused by opioid overdose in the late 1990s prompted more calls for a heroin trial.3 The Federal Government refused to countenance a trial, creating a policy deadlock that prevented the evaluation of what proponents2 claimed was a potentially valuable policy option.

If we can avoid the fixation on a trial of heroin per se, there is a way out of this policy deadlock. The alternative option we are proposing is to trial hydromorphone (Dilaudid), an injectable opioid that has similar effects to heroin.4,5 Even if the Federal Government's attitude towards a heroin trial were to change, we believe that trialling hydromorphone would be a better option than trialling heroin, for a number of reasons:

• The subjective effects of hydromorphone are very similar to heroin in experienced heroin users and both have short durations of action.5

• Hydromorphone is a registered drug (Schedule 8) in Australia, so it can be prescribed for medical purposes and used in clinical trials. There would be no need to change federal legislation to allow a trial of injectable hydromorphone. Nor would there be any need for oversight of heroin importation and distribution by the International Narcotics Control Board.

• The use of hydromorphone can be distinguished from the use of heroin by urinalysis,6 thus allowing detection of any covert use of street heroin by trial participants. (A major criticism of the Swiss heroin trials was that this could not be done.)4

• Hydromorphone lacks the political symbolism of heroin.5 This would allow a clinical trial to be conducted in the absence of the media sensationalism that would probably attend a trial of heroin maintenance. A protocol for a clinical trial of hydromorphone could be assessed by peer review and funded by the National Health and Medical Research Council. (On the other hand, a trial of hydromorphone might have the disadvantage of discouraging participation of dependent heroin users who only want heroin. Assessing the attractiveness of hydromorphone to the patient population would therefore be an important part of a feasibility study for a clinical trial.)

• A trial of hydromorphone may reduce the need to inflate the public health benefits of heroin maintenance in order to enlist community support for a heroin trial. Allowing the prescribing of injectable opioids, whether heroin or hydromorphone, would be unlikely to substantially reduce the heroin black market or heroin-related crime. The cost of providing this form of treatment, and the restrictions that the community would probably impose on eligibility for it, mean that too few heroin-dependent people would receive this form of treatment to have a substantial effect on heroin use and its consequences in the population.7 Injectable opioid maintenance would most likely be a treatment option reserved for dependent heroin users who have failed at existing forms of treatment (the model that was trialled in Switzerland).8

Any trial of hydromorphone maintenance for opioid dependence should include an economic evaluation of the comparative costs and benefits of competing forms of maintenance treatment. These could include alternative forms of injectable opioid maintenance using longer-acting agonists such as methadone and partial agonists such as buprenorphine. Oral methadone maintenance should be the comparison condition, as in a recent trial of heroin maintenance.9

For these reasons, we believe a controlled clinical trial of injectable hydromorphone maintenance would break the impasse over a heroin trial and enable the Australian community to decide what role injectable opioid maintenance has to play in the public health response to dependent opioid use.