HEPATOTOXICITY FROM PARACETAMOL SELF-POISONING IN WESTERN SYDNEY - A CONTINUING CHALLENGE

Objective: To determine the annual incidence of admissions for paracetamol overdosage in the years 1985 to 1990, morbidity and mortality rates, predictors of poor prognosis and the most appropriate use of N-acetylcysteine (NAC). Design: A retrospective review of case records of all patients with a discharge diagnosis of paracetamol overdosage. Setting: A 900-bed tertiary referral teaching hospital in western Sydney with a busy accident and emergency department. Patients: 306 patient records were reviewed and details of the overdose and admission were recorded. Interventions: NAC infusion in patients with possible paracetamol hepatotoxicity. Main outcome measures: Blood paracetamol levels; elevated alanine aminotransferase levels; prolonged prothrombin time; severe liver injury; and NAC side effects. Results: Annual admission rate was constant at circa 55 per annum. Female to male ratio was 2:1. Predictors of liver injury included paracetamol dose over 10 g, presentation more than 10 hours after the overdose and chronic ingestion of more than 80 g alcohol per day. There were no deaths. Fifty-five patients (18%) had toxic paracetamol levels, 51 % received treatment with NAC, including 40% of those with non-toxic levels, and 11% of those treated with NAC experienced side effects. Conclusion: Paracetamol overdosage continues to be a significant cause of hospital admissions in western Sydney. Severe hepatic damage occurs infrequently and the prognosis for liver injury, when it occurs, is good. Treatment with NAC should be reserved for patients with definite indications for the drug.