November 2021

Lethal cocktails: poly-drug mixes the common denominator in overdose

Combinations of substances, rather than any one drug or even drug type alone, are responsible for the majority of fatal overdoses in Australia, analysis of the nation’s coronial findings reveals.

Frontline workers advising on or responding to unintentional overdose are more likely than ever to encounter multiple substance groups – in fact, four or more in more than a quarter of all cases.

The continued prevalence of poly-drug use is revealed in Australia’s Annual Overdose Report 2021, released by Penington Institute on August 31 to coincide with International Overdose Awareness Day.

In 2019, Australia lost at least 2,227 people to preventable overdose – and at least 1,664 of these deaths were unintentional. In reality, both figures – taken from Australian Bureau of Statistics data and classed as preliminary at this stage – will rise in the next 18 months as coronial investigations across the eight states and territories are finalised.

Drug-induced deaths first surpassed the road toll nationally in 2014 and since that time have consistently and clearly outstripped both car and general land transport (including farm machinery) accidents as a major cause of death, particularly among 30–49-year-olds.

Drug-induced deaths first surpassed the road toll nationally in 2014 and since that time have consistently and clearly outstripped both car and general land transport (including farm machinery) accidents as a major cause of death, particularly among 30–49-year-olds.

Strikingly, more than two-thirds of deaths – both unintentional and suicide – now involve two or more substance types, and in the five years to 2019 almost one in 10 unintentional fatalities involved at least six.

What does this mean for those working in health care and the emergency services?

The fact drugs other than opioids are present may reduce the efficacy of naloxone (which engages only with the body’s opioid receptors) in reversing overdose. First responders are likely to find that patients have used a combination of pharmaceutical and/or illicit drugs, plus potentially alcohol as well (itself a central nervous system depressant).

In people who died by drug-induced suicide in 2019, benzodiazepines and anti-depressants appeared marginally more often than opioids as the ‘big three’ contributors.

These were also the top three substances in unintentional overdose deaths; however, opioids were clearly more common here (in 83.2 per cent of cases), split almost exactly 50/50 between pharmaceutical and illicit opioids. Stimulants, cannabinoids and anti-psychotics were each identified in at least one in five deaths.

Most drug-induced deaths are caused by a combination of drugs and are not the result of a single drug; most drugs determined to have contributed to a death in 2019 were used concurrently with other drugs

John Ryan

“Most drug-induced deaths are caused by a combination of drugs and are not the result of a single drug,” says John Ryan, CEO of Penington Institute, which publishes Australia’s Annual Overdose Report. “For example, benzodiazepines have been recorded as the second most common drug group associated with drug-induced deaths, but they are rarely the sole cause of death. Most drugs determined to have contributed to a death in 2019 were used concurrently with other drugs.”

People born in Australia are more than six times more likely to die of unintentional drug overdose than those born in Asia, with rates of 8.7 people per 100,000 and 1.4 per 100,000 respectively; in between sit those from Europe 5.5/100,000), Oceania (5.2/100,000), the Americas (4.8/100,000) and Africa and the Middle East (3.3/100,000). The pattern is similar, albeit at far lower rates, in suicides, which are examined in the report for the first time this year.

The rate of overdose death is noticeably higher in regional and rural areas than in capital cities – 7/100,000 compared to 6.1/100,000 – and men are twice as likely as women to experience fatal overdose.

Disproportionate rate

Shockingly – if perhaps not surprisingly for those on the front line – the rate of overdose death among Aboriginal and Torres Strait Islander people is almost four times that seen among non-Indigenous Australians: 20 versus 5.9 per 100,000 individuals nationally.

In the 2015–19 period, the difference is most pronounced for stimulants, with a rate of 6.5 per 100,000 Aboriginal people compared with 1.7 per 100,000 non-Aboriginal people.

“In the five years from 2015 to 2019, 515 Aboriginal and Torres Strait Islander people died of unintentional overdose,” Scott Wilson, CEO of the Aboriginal Drug and Alcohol Council (South Australia) and a Penington Institute Board member, says. “Over the same time, the rate of unintentional overdose deaths was higher for Aboriginal people in every drug type category.

“This discrepancy requires our urgent and sustained attention. Rates of overdose death among Aboriginal people have been increasing since 2009 and too many of our leaders are missing in action.”

Scott says understanding why Aboriginal and Torres Strait Islander people suffer such disproportionate overdose deaths is inextricably linked to the wider issues of health and wellbeing, including economic security, housing stability, access to services and generational trauma.

“Despite broad similarities, there are key differences in the demographics of Aboriginal Australians dying from overdose as well as the drugs involved,” he says. “A higher share of Aboriginal people are dying from overdose at younger ages: 41 per cent of deaths from 2015 to 2019 occurred among Aboriginal people aged 20–39, with just 10 per cent occurring among people aged 60 and older. Among non-Aboriginal Australians, 30 per cent of deaths were among those aged in their 20s and 30s while 21 per cent of overdose deaths occurred among those aged 60 and older.

“Aboriginal and Torres Strait Islander Australians don’t need our protection or paternalism but they do need real input into the decision-making that affects their health and safety.”

‘One million overdoses’

“Overdose hides in plain sight,” John Ryan says.

“If there are 30 non-fatal overdoses for every fatal one, as research suggests, then there have been approximately one million overdoses this century. Drug and alcohol poisoning – a category which is overwhelmingly made up by drug overdoses – is the second-leading cause of death for Australians in their 30s while for those in their 20s and 40s it’s the third-leading cause of death.

Drug and alcohol poisoning is the second-leading cause of death for Australians in their 30s while for those in their 20s and 40s it’s the third-leading cause of death.

John Ryan

“Combining the Commonwealth’s own estimate of the value of a year of life lost with the average of 33 years of life lost for each overdose death means that this alone costs our economy more than $15.5 billion every year. The cost to the families who lose a loved one is impossible to calculate.”

John encourages health services to share these statistics both directly with clients and with the broader communities in which they operate, including via mainstream and social media channels.

To obtain Australia’s Annual Overdose Report 2021 as a PDF, visit the Penington Institute website.