Unintentional drug-induced death involving anticonvulsants and neuropathic pain modulators such as pregabalin and gabapentin are rising in Australia at ‘dramatic’ rates, according to Australia’s annual overdose report.
The two drugs are associated with the majority of deaths of the drug class, which have risen from zero to one in ten of the unintentional drug-induced deaths in recent years, according to the Pennington Institute report that covers 2,227 overdose deaths in 2019.
The report found that anticonvulsants were implicated in 154 of 1644 unintentional overdose deaths in 2019. Opioids were the most common drug involved (882 deaths) followed by benzodiazepines (582), stimulants (470), antidepressants (340), cannabinoids (256) and antipsychotics (197).
Pregabalin was more commonly prescribed in Australia than gabapentin, and prescribing rates for pregabalin were increasing considerably, the report found. Despite being coded as anticonvulsants both drugs and commonly prescribed for chronic neuropathic pain and, more commonly, off-label for a range of pain conditions.
The rate of death associated with the two drugs was zero across metropolitan and regional areas prior to 2015 but in the five years between 2015 and 2019 that figure jumped to 0.6 per 100,000 population in capital cities. Outside of capital cities the rate shot up to 0.7.
There were 312 deaths among males during the five-year period, accounting for 62% of all such deaths, compared with 193 deaths among females.
Western Australia bore the greatest burden of death in 2019, with 1.2 deaths per 100,000 population followed Queensland with 0.9 deaths per 100,000 population
While the rate itself was low, the increase was dramatic, the reports authors warned, adding that such increases may well be occurring across other parts of the country but different post-mortem toxicological procedures could mean the trend has gone undetected.
Deaths involving the anti-convulsants were highest among people aged 40-49, accounting for a third (32.9%) of all unintentional deaths. Three in ten deaths (29.7%) were seen among those aged 30-39, while more than one-quarter (26.9%) of the unintentional deaths involving anti-convulsants were recorded among people aged 50 and over. Deaths among people aged under 30 accounted for 10.3% over the five-year period.
Despite the observed increases in some jurisdictions in the rate of unintentional drug-induced deaths involving anti-convulsants, the death rate remains far lower than for other drug types.
John Ryan, CEO of the Pennington Institute, said the findings highlighted the importance of tackling overdose deaths, which now exceeded the annual road toll.
“This year’s Annual Overdose Report contains many findings that should prompt a shift in our approach, to drug policies based on lived experience and research. The best place to begin is with a National Overdose Prevention Strategy, developed in close collaboration with people with lived experience, frontline workers and other experts,” he said.
“It must fearlessly address the drivers of drug use, the diversity of drugs that are causing overdose and how overdose risks are evolving. This strategy must be developed carefully but – crucially – it must also be developed urgently.”
Australia’s annual overdose report 2021 can be accessed here.