Paracetamol intoxications: A population-based study in Iceland

Background: Paracetamol is the most common cause of acute liver failure (ALF) in the US and many countries in Europe. Most data on paracetamol toxicity originate from liver transplant centres and tertiary referral institutions. The proportion of patients with paracetamol overdose who develop liver injury in a population-based sample is largely unexplored. The aim of this MPH thesis was to analyze the population-based annual incidence of paracetamol overdoses, prevalence of liver injury and the risk factors for hepatotoxicity and outcome in unselected patients presenting to hospital with paracetamol toxicity and/or overdose Methods: This was a retrospective and descriptive cohort study. Search for the diagnosis of paracetamol toxicity and liver failure was undertaken in a teaching hospital serving a population of approximately 220,000 inhabitants in Iceland over a six-year period, from 2004 to 2009. Medical charts were reviewed for relevant characteristics, the proportion of intentional vs. unintentional toxicity, liver tests and outcome. Results: In this population-based study 1913 visits were reviewed, and 346 (18%) involved paracetamol overdoses. The annual population incidence for all drug-related overdoses over the six years declined from 200.5 to 117.3 per 100,000 inhabitants (p<0.001). Likewise, the annual incidence of paracetamol overdoses declined from 32.8 to 17.3 per 100,000 inhabitants (p<0.05). The female/male ratio in the paracetamol cases was 2.8. The largest age-group by far was 16-25 years with 40% of the total cases. There were 290 index visits by patients over the age of ten. The female to male ratio was 2.7. Of the total cohort 22% were admitted to the acute medical ward, and 11% needed intensive care. N-acetylcysteine was administrated in 59% of the cases. Twenty-five percent were discharged directly home after presentation to the emergency room. There was acute ethanol consumption in 41% of the cases. Visits caused by accidental overdoses constituted 7% (20/285) of the total cohort. Males were more likely to overdose due to therapeutic misadventures for medical effects (p<0.05). The accidental group had higher peak aminotransferase levels (p<0.005) in spite of lower serum paracetamol P<0.05). There was acute liver failure (ALF) in 3.1% (9/290) of the index visits. The proportion of males was higher although not significantly so (p=0.07). The median age for males was also higher (p<0.05). In the intentional group 1.5% developed ALF, compared to 15% of the accidental group (p<0.05). Only one patient died from ALF. Conclusions: The annual incidence of paracetamol toxicity was high in this population-based study but declined over the period. Young females with intentional toxicity accounted for most of the cases, whereas accidental toxicity was more common in older males. The occurrence of ALF was low and associated with accidental overdose. The use of NAC was very frequent, and serious outcomes were very rare. Most patients had favourable outcomes.

Author dc:creator

• Ingibjörg Kjartansdóttir 1958-

Contributors dc:contributor

• Háskóli Íslands

• Lýðheilsuvísindi
• Lifur
• Lyfjaeitranir

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/1946/10435

OAI identifier oai:identifier

oai:skemman.is:1946/10435