A powerful anti-anxiety drug has been involved in a rising number of heroin-related deaths (HRDs) in Victoria in recent years, according to new research.
In a paper published in the Medical Journal of Australia today, researchers from Monash University called for the prescription and scheduling of the benzodiazepine alprazolam to be examined, after their study uncovered a dramatic increase in the supply of this drug, and detection in a rising rate of HRDs.
The findings come weeks before the Therapeutic Goods Association is due to meet to discuss whether more restrictions should be placed on the availability of benzodiazepines.
Alprazolam is a psychoactive drug approved for the short-term treatment of anxiety and panic disorder in Australia. Alprazolam is not recommended as a firstline treatment for these conditions due to concern about dependence, the potential for its misuse and because non-pharmaceutical interventions, such as cognitive behavioural therapy, have been found to be more effective.
Highly potent, with rapid onset and offset of action, alprazolam may also be more toxic in overdose than other benzodiazepines – a class of drug taken by heroin users to enhance the intoxication effects of opioids, or manage anxiety or withdrawal symptoms.
However, using the Australian Statistics on Medicines and data from Medicare, the researchers calculated that the supply of alprazolam increased by 1426 per cent between 1990 and 2010.
In the same period, there were 2392 HRDs in Victoria, peaking at 362 in 1999 when there was a large supply of heroin. Until 2004, the rate of alprazolam detection in HRDs wavered between 0 and 4.4 per cent (or two deaths), but then rose steadily to 28.1 per cent of HRDs (or 27 deaths) in 2010.
Lead researcher Angela Rintoul, a Doctor of Public Health candidate in the Monash University School of Public Health and Preventive Medicine said the research showed that measures to improve the quality of the supply of alprazolam should be implemented.
“Despite being a second-line treatment for anxiety, alprazolam supply has risen dramatically, with a disproportionate increase in the highest – 2mg – dose formulation,” Ms Rintoul said.
“A survey of injecting drug users has shown that alprazolam use in this population increased from eight per cent to 69 per cent between 2005 and 2011. More than 80 per cent of this supply was obtained illicitly.”
In addition to its increased involvement in HRDs, alprazolam use by people who inject drugs is associated with amnesia, violent outbursts in otherwise non-violent people, and theft.
“Measures such as education of health professionals and people who inject drugs, more restrictive scheduling of alprazolam and better monitoring and surveillance should all be considered to improve alprazolam supply and mitigate the associated harm,” Ms Rintoul said.