Unintentional acetaminophen ingestion in children and the potential for hepatotoxicity

Children who unintentionally ingest acetaminophen are often referred to health care facilities for evaluation. Criteria for referral are not well defined and the vast majority of these exposures result in nontoxic serum concentrations. The objective of this study was to determine the incidence of potentially hepatotoxic serum concentrations and to more clearly define referral criteria for these patients.

A prospective evaluation of all childhood (age 1-72 months) single ingestions of acetaminophen-containing products was performed by the Utah Poison Control Center. All patients ingesting 140 mg/ kg or greater or an unknown amount were referred for medical evaluation. Patients who ingested greater than 100 mg/kg were advised to administer syrup of ipecac at home if less than 1 hour since ingestion. Activated charcoal was recommended within 2 hours of ingestion if the patient was already at a health care facility. The potential for hepatotoxicity was assessed according to the Rumack-Matthew nomogram.

Inclusion criteria were met by 1015 patients. The mean age was 28 +/- 12 months and mean dose was 213 +/- 148 mg/ kg. Decontamination with ipecac, gastric lavage, or activated charcoal within 2 hours of ingestion occurred in 81% of patients ingesting greater than 140 mg/kg or an unknown amount. Six patients (0.59%, 95% CI 0.12-1.16%) had "possible" or "probable" hepatotoxic serum concentrations and all had ingested greater than 200 mg/kg or an unknown amount. There were 423 patients who ingested between 100 and 200 mg/kg and none had potentially hepatotoxic serum concentrations (upper 95% CL 0.71%).

Children who ingest between 140-200 mg/kg of acetaminophen and demonstrate ipecac-induced emesis within 60 minutes may be safely managed at home. Patients ingesting greater than 200 mg/kg or an unknown amount should be referred for a serum acetaminophen concentration.