Paracetamol self-poisoning: Epidemiological study of trends and patient characteristics from the multicentre study of self-harm in England

Background
Paracetamol is frequently used for intentional self-poisoning, especially in the UK, despite pack size restrictions introduced in 1998. Knowing more about paracetamol self-poisoning may identify further approaches to prevention.

Methods
We used data from the Multicentre Study of Self-harm in England for 2004–2014 to calculate incidence rates of presentations to Emergency Departments following self-poisoning with pure paracetamol alone. National estimates for England for 2011–2014 were extrapolated using indirect age-standardised rates. The characteristics of individuals taking paracetamol overdoses and the size of the overdoses were investigated.

Results
A third of 54,863 intentional overdoses presenting to the five Emergency Departments involved paracetamol without other drugs (N = 18,011), taken by 13,171 individuals (63.4% female). The proportion of paracetamol self-poisonings was similar in the three centres. Extrapolation suggested there were approximately 50,000 paracetamol overdoses in England annually during 2011–2014. Females had higher rates of paracetamol overdose than males. Males and older individuals took larger overdoses. Nearly a quarter of individuals (24.2%) consumed more than 32 tablets. Alcohol was involved in 53.7% of paracetamol overdoses.

Limitations
Data were collected in three centres with predominantly urban populations. Extrapolation from local to national rates should be interpreted with caution.

Conclusions
Paracetamol overdose remains a major problem in the UK. It is more common in females and younger patients, but males and older patients consume larger overdoses. Consideration should be given to further restriction in pack sizes and sources of sales, in keeping with those of several other European countries.