July 2026
Repeat poisoning risk high after paracetamol overdose
By Sasha Ellery BA, BM BCh
Intentional paracetamol poisoning admissions in New South Wales are common and carry a substantial risk of repeated poisoning and long-term mortality, despite serious liver injury being uncommon in this group, new research finds.
In a retrospective linked-data cohort study published in The Lancet Regional Health – Western Pacific, researchers analysed 24,092 paracetamol poisoning admissions involving 19,895 individuals in NSW hospitals between January 2011 and September 2020. Most admissions were intentional (78.8%) and occurred in women (71.0%); the median age was 29 years.
Speaking to Medicine Today, Associate Professor Rose Cairns, senior author of the paper and Associate Professor in the Faculty of Medicine and Health, The University of Sydney, said, ‘Paracetamol is the most common substance taken in overdose and is a leading cause of acute liver injury… While the TGA introduced some recent pack size changes in 2025 targeted at reducing harm from intentional overdose, toxic doses of paracetamol are still readily available in front of the counter in pharmacies.’
The study found intentional poisonings were most common among young people, with females aged 15 to 19 years the largest subgroup. People admitted after intentional poisoning had high rates of anxiety, mood disorders and psychoactive substance use.
Liver injury was more common after accidental poisoning than intentional poisoning, occurring in 6.1% versus 1.5% of admissions, respectively. The authors suggested accidental cases may involve delayed presentation, inadequate pain control, dosing errors or concurrent use of multiple paracetamol-containing products.
Among people with an intentional paracetamol poisoning admission, 21.8% had a repeat intentional poisoning, with most initial repeats occurring within one year.
‘Things like check-ins and other interventions could be targeted to this high-risk period immediately following an overdose,’ explained Associate Professor Cairns.
She noted that paracetamol was often the substance people took in their first ever overdose, but method-switching was common in subsequent overdoses, with people often taking other medicines.
People with multiple repeat poisonings had higher rates of psychiatric and substance use comorbidities and poorer long-term survival. By the end of the follow-up period, 7.6% of people with more than one repeat intentional poisoning had died, compared with 4.7% of those with no repeat intentional poisoning.
The authors said their findings highlighted the need for health-system responses focused on postoverdose management and continuity of mental health support after intentional paracetamol poisoning.
‘When looking at long-term outcomes following intentional overdose, people are at elevated risk of death from suicide, but also many other causes of death – like unintentional poisoning and many natural-cause deaths,’ said Associate Professor Cairns. ‘While assessing someone’s mental health is important, it’s also an opportunity to assess a person’s substance use and other medical and social issues which could contribute to this excess risk.’