PARACETAMOL overdose is on the increase in Australia, say researchers who are calling for pack size restriction in addition to rescheduling of modified release paracetamol to pharmacist-only from June 2020.
In research published in the MJA, researchers found that the annual number of paracetamol poisoning-related hospital admissions between 2007–08 and 2016–17 had increased by 44.3% or about 3.8% per year. The number of associated cases of toxic liver disease increased by 7.7% per year.
The researchers analysed data from the Australian Institute of Health and Welfare National Hospital Morbidity Database, the NSW Poisons Information Centre (NSWPIC) and the National Coronial Information System and identified more than 95 000 hospital admissions with a diagnosis of paracetamol poisoning over the study period.
They noted that the number of paracetamol-related deaths (annual mean, 43 per year; range, 34–57 deaths per year) had remained steady over the decade, which they said might reflect improved treatment guidelines.
Reports to the NSWPIC had also increased, with almost 23 000 reports of intentional overdoses with paracetamol received between 2004 and 2017, an increase of 77% or 3.3% per year.
The findings come after the Therapeutic Goods Administration (TGA) announced a rescheduling of modified release tablets or capsules containing 665 mg of paracetamol or less from pharmacist-only (S2) to pharmacist-only (S3) from June 2020.
The MJA research showed that modified release paracetamol was implicated in 9.5% of overdoses during 2009–2017 and in 33% of the fatal overdoses.
Dr Angela Chiew, Emergency Physician and Clinical Toxicologist at Sydney’s Prince of Wales Hospital and the NSW Poisons Information Centre, said a key concern in the MJA findings was the increasing size of the overdoses.
“The overdose size is increasing, and the modified release data are very telling because the majority of the pack sizes are 96 tablets and they are [responsible for] much bigger overdoses,” she said, pointing to the finding that overdoses with modified release paracetamol were larger than for immediate release formulations.
Dr Chiew said that, in a submission to the TGA on paracetamol scheduling, she had called for all paracetamol packs of 20 tablets or more to be up-scheduled from S2 to S3.
The MJA researchers found that the median age of overdose was 18 years, and Dr Chiew said this was consistent with recent Australian research published recently in BMJ Open that found that girls born after 1997 were at particular risk of self-harm using paracetamol.
“I think anything more than 20 tablets should be pharmacist-only [S3] because the people we want to help reduce harm in is these young teenage girls,” she said. “I went into a chemist and bought 500 tablets for $10 and nobody stops you and asks you a question, you just go in and buy large amounts.”
In the UK paracetamol pack sizes have been restricted to 8 g for non-pharmacy sales and 16 g for pharmacy sales since 1998. The MJA researchers said the restrictions had been effective in reducing overdose, liver unit admission, and suicide in England and Wales, but had had little impact in Scotland.
Professor Andrew McLachlan, Head of School and Dean of Pharmacy at the University of Sydney’s School of Pharmacy, said it was important to view these latest data in the context of the overall safety of paracetamol in pain management.
“[Paracetamol] is a commonly used analgesic that does provide benefit for pain and fever for many people,” Professor McLachlan told InSight+. “When people think that paracetamol is more dangerous, they might reach for other [medicines] which we know to be more harmful, such as non-steroidal anti-inflammatories and, of course, opioid medicines.”
However, he said, it was concerning to see increasing paracetamol-related harms in Australia, and pack size restrictions, as well as consideration of the appropriateness of the unrestricted sale of 20-tablet packs in supermarkets, could play a role in arresting this trend.
“The data internationally point to the fact that if you have smaller pack sizes, then the opportunity for people to self-harm using paracetamol starts to be substantially reduced and … that alone provides merit for the regulators to consider where those packets are unrestricted, outside of a pharmacy,” he said.
But Professor McLachlan acknowledged that the retailing practices of some pharmacists in the past had drawn criticism.
“I wouldn’t let my pharmacy colleagues off the hook,” he said. “I know that some discount pharmacy chains do provide large packets of paracetamol – 100 tablets—often at very low prices, as loss leaders. Medicines are not normal items of commerce and they should not be promoted in that way, but I think that certainly has been changing.”
Carol Bennett, CEO of Painaustralia, said her organisation had supported the TGA’s decision to up-schedule modified release paracetamol, and it was important that patient education measures were also prioritised in improving the safety of paracetamol use in Australia.
“We were comfortable with the decision to up-schedule modified release paracetamol to Schedule 3; however, we don’t think pharmacists’ advice alone will be enough to alert people to some of the risks associated with this product,” Ms Bennett told InSight+.
“There is a need for better information – not just the pharmacist advising because that can be variable – but actually labelling packs and making sure there is ready availability of information for consumers.”
Ms Bennett said there were “pluses and minuses” in reducing paracetamol pack sizes.
“It could be useful, but the difficulty we see is that many consumers benefit from the cost effectiveness of larger pack sizes,” she said. “I know that might seem at odds with quality use of medicines, but the reality is that many older people with osteoarthritis struggle to pay for their health care needs, particularly OTC pharmaceuticals.”
She said patient education and awareness of non-pharmaceutical pain management options were crucial and would be a feature of the updated National Pain Action Plan, which was expected to be approved by Australian Health Ministers later this year.
“[The plan is] about changing the mindset and the culture of chronic pain being managed with medication alone because that is not best practice.”
Professor McLachlan said he had co-authored several studies in recent years (here, here, and here) that had shown that paracetamol provided no, or minimal, benefit in the management of low back pain and osteoarthritis.
“Now more than ever, we have the quality information to say the long-term use of paracetamol in those health conditions perhaps isn’t providing the benefit that we always had assumed it was,” he said. “And that does point to the fact that the long term use of paracetamol, while it’s very safe – probably isn’t providing a huge amount of benefit.”