Australasian Science: Australia's authority on science since 1938

Call to rethink anti-anxiety drug

A huge increase in the involvement of the anti-anxiety drug alprazolam in heroin-related deaths has led to calls for investigations into inappropriate prescribing and illicit supply in the Medical Journal of Australia.

Alprazolam, a benzodiazepine registered in Australia for the short-term treatment of anxiety and panic disorder, is not recommended as a first-line treatment because of concerns about the risks of dependence and misuse.

Despite these recommendations, the drug has been detected in an increasing number of heroinrelated deaths, according to Angela Rintoul, a Doctor of Public Health candidate in the Department of Epidemiology and Preventive Medicine at Monash University in Melbourne, and her coauthors.

According to Victorian data from the national Illicit Drug Reporting System, a regular survey of people who inject drugs, “recent alprazolam use increased from 8% in 2005 to 69% in 2011”, the authors wrote.

The number of alprazolam detections [in heroin-related deaths] in Victoria increased steadily from 2004 (2), reaching a peak in 2010 (27), they reported. Alprazolam has a rapid onset and offset, high potency and may be more toxic in overdose than other benzodiazepines. It has been associated with disproportionate levels of harm, including amnesia, violent outbursts of rage in otherwise non-violent people and crime.

One reason it is favoured by people who inject drugs is for enhancing the intoxicating effects of heroin.

“In Victoria, most alprazolam (81%) used by people who inject drugs in 2011 was obtained from illicit sources”, the authors wrote.

The authors studied Victorian data from 1990 to 2010 and found a number of trends in alprazolam prescribing, supply and its relationship to heroin-related deaths.

“First, the supply of alprazolam increased despite its status as a second-line treatment for its approved indications”, the authors wrote. “Second, the increase in the supply of the high-dose [2 mg] formulation was disproportionate to the increase in other formulations.

“Third, the rate of detection of alprazolam in heroin-related deaths increased more rapidly after 2005, concurrently with other reports of increasing harm among people who inject drugs”, they said.

“This raises questions about the increased prescribing of a drug not preferred for treatment of its primary indication and for which little evidence exists for effectiveness beyond short-term use.

“Given the growing concerns … supply control measures — such as better monitoring and surveillance (including real-time prescription monitoring), rescheduling to Schedule 8, and education of health professionals — are warranted”, the authors wrote.

The Medical Journal of Australia