Objective: To examine the incidence and severity of paracetamol poisoning in a population-based cohort in Iceland. A previous study showed a decrease in the incidence during a financial crisis in Iceland, by approximately half (16/100,000 annually). The aims of the study were to assess the incidence and nature of paracetamol poisoning after economic recovery in Iceland and to compare intentional and accidental poisoning.
Methods: Paracetamol serum concentrations were used to identify patients in this retrospective study from 2010-2017. A search was undertaken in laboratory databases for patients with serum paracetamol concentrations, which were grouped by <66 µmol/L (below detection limit) and ≥66 µmol/L. Medical records were reviewed and relevant laboratory and clinical information obtained to determine whether paracetamol poisoning had occurred.
Results: Altogether 542 cases of paracetamol poisoning were identified. The mean annual incidence was 27/100,000 (range 22-33). Intentional poisoning was observed in 437/542 (81%) cases, most frequently among females 16-25 years of age. Males ≥65 years were more likely to overdose by accident, which was associated with worse outcomes. Twenty-five (4.6%) patients developed severe paracetamol-induced liver injury and coagulopathy. Overall, six (1.1%) cases were fatal in which paracetamol contributed to the cause of death, with accidental poisoning found in 67% (4/6).
Conclusions: The incidence of paracetamol poisoning has increased in recent years associated with economic recovery in Iceland. Most patients had favourable outcomes. Intentional overdose was most common in young females, whereas accidental overdose was more common in older males and more frequently associated with a fatal outcome.
Keywords: Accidental; acute liver failure; epidemiology; incidence; intentional; liver injury; overdose; paracetamol (acetaminophen); poisoning.