Related Experiment Videos
Predicting concentrations in children presenting with acetaminophen overdose
B J Anderson1, N H Holford, J C Armishaw
1Department of PICU, Auckland Children's Hospital, Park Road, Grafton, Auckland, New Zealand.
Insights
For children aged 1-5 years with acetaminophen elixir overdose, measuring serum concentrations at 2 hours post-ingestion, not 4 hours, is recommended. Enteral charcoal is ineffective after one hour.
Area of Science:
- Pediatric toxicology
- Pharmacokinetics
- Clinical pharmacology
Background:
- Accidental acetaminophen ingestion in children requires accurate toxicity assessment.
- Current guidelines for monitoring acetaminophen toxicity may not be optimal for young children.
Purpose of the Study:
- To predict serum acetaminophen concentrations in children (1-5 years) following accidental ingestion.
- To evaluate and potentially improve existing treatment guidelines for pediatric acetaminophen overdose.
Main Methods:
- Pharmacokinetic modeling was used to simulate acetaminophen concentrations in 1000 children.
- Simulations considered a 300 mg/kg dose and age-specific variability.
- Predicted concentrations were validated against data from 121 children with accidental ingestion.
Main Results:
- Simulations predicted a 300 mg/kg dose would yield 32-208 mg/L (95% CI) at 4 hours.
- Maximum acetaminophen concentrations typically occurred before 2 hours in simulated pediatric cases.
- Enteral charcoal administration >90 minutes post-ingestion showed no significant impact on serum levels.
Conclusions:
- For children (1-5 years) ingesting >250 mg/kg acetaminophen, serum concentration measurement at 2 hours is advised over the adult 4-hour recommendation.
- This earlier measurement can expedite patient discharge and reduce parental anxiety.
- Enteral charcoal is only effective if administered within one hour of acetaminophen ingestion.
Objective:
To predict serum concentrations to evaluate and improve guidelines for the treatment of children (1 to 5 years) with accidental ingestion of acetaminophen elixir.
Methods:
Acetaminophen concentrations for 1000 children were simulated with pharmacokinetic parameters and their expected variability. The distribution of concentrations arising from a 300 mg/kg dose at different age groups was predicted. These predictions were validated by comparison with concentrations obtained at 4 hours from 121 children with accidental ingestion of acetaminophen elixir.
Results:
No child who presented with overdose had a concentration in the probable risk area of the Rumack-Matthew toxicity nomogram. Enteral charcoal administered 98 minutes (SD 44) after ingestion had no effect on serum concentrations. The simulation predicted that an acetaminophen dose of 300 mg/kg would result in concentrations of 32 to 208 mg/L (95% CI) at 4 hours after ingestion. The maximum concentration occurred before 2 hours in 95% of simulated children.
Conclusion:
Children (1 to 5 years) with reported ingestion of >250 mg/kg acetaminophen elixir should have serum concentrations measured at 2 hours after ingestion rather than at the 4-hour time point recommended in adults. This can be expected to speed discharge and reduce anxiety. The use of enteral charcoal is unlikely to enhance acetaminophen elimination, unless it is given within an hour of acetaminophen ingestion.