Objective
The prevalence of benzodiazepine injection increased in several Australian jurisdictions in the early part of the decade. This was associated with substantial venous harms and increased overdose risk. Availability restrictions for temazepam gel capsules, the formulation predominantly injected, through the Pharmaceutical Benefits Scheme (and subsequent removal from the market) produced sustained reductions in rates of benzodiazepine injection in most jurisdictions. However, in Tasmania, an isolated drug market with low heroin availability, rates of benzodiazepine injection remained unchanged. Alprazolam was substituted in place of temazepam, with multiple cases of mortality and serious morbidity associated with alprazolam injection identified recently. In September 2007, the regulatory status of alprazolam was changed in Tasmania from Schedule 4(D) to effectively be Schedule 8 for people prescribed any opioid, whereby authority for prescription was required. The number of available drug treatment places was unchanged. This paper aims to examine the impact of this policy change in the nine months following its implementation.

Methods
Alprazolam prescription data was obtained from the Drug-Utilisation Subcommittee, Medicare Australia and Tasmanian Pharmaceutical Services Branch. Patterns of recent drug use among convenience samples of people that regularly inject drugs (IDU) interviewed in the Tasmanian Illicit Drug Reporting System 2005-2008 (n=100 per annum) were examined.

Results
Increasing prescription rates of alprazolam in Tasmania were reversed following the changes to the regulatory status. For those accessing alprazolam without prescription, availability similarly reduced and price increased. However, there has been no evidence of a change in the extent of alprazolam injection amongst IDU in the nine months since the regulatory change, the group directly targeted by this policy intervention.

Conclusions
Policy interventions designed to reduce harms associated with non- or not-as- prescribed pharmaceutical use must be carefully targeted and mindful of the broader drug market context in order to achieve their aims.