Intravenous Acetaminophen Overdose in an Infant With Toxicokinetic Data

Area of Science:

• Pediatric Pharmacology
• Clinical Toxicology
• Neonatal Pharmacokinetics

Background:

• Intravenous acetaminophen (APAP) is increasingly used for pain management in pediatric patients.
• Accidental medication errors can occur, particularly in vulnerable populations like neonates.
• Understanding the toxicokinetics of APAP in infants is crucial for managing overdose scenarios.

Observation:

• A 12-month-old infant (24-week gestational age) inadvertently received 1000 mg of IV acetaminophen instead of 100 mg.
• Serial acetaminophen concentrations were monitored post-administration.
• The infant was treated with intravenous N-acetylcysteine.

Findings:

• The patient exhibited no adverse outcomes following the acetaminophen overdose.
• Calculated elimination rate constant (ke) was 0.263 h-1, resulting in a half-life of 2.63 hours.
• This half-life aligns with the reported range of 2.6 to 4.9 hours for IV APAP in infants, though variability reasons remain unclear.

Implications:

• This case contributes to the limited data on IV acetaminophen toxicokinetics in preterm infants.
• Prompt administration of N-acetylcysteine appears effective in preventing toxicity even after significant overdose.
• Further research is warranted to elucidate the factors contributing to the variable half-life of IV APAP in this population.