Acetaminophen Dosing for an 8.9kg Infant
For an 8.9kg infant, administer acetaminophen 10-15 mg/kg per dose (89-134 mg) every 6 hours, with a maximum daily dose of 60 mg/kg (534 mg/day). 1
Specific Dose Calculation
- Per dose range: 89-134 mg every 6 hours 1
- Practical dosing: Start with 10 mg/kg (89 mg) and increase toward 15 mg/kg (134 mg) if needed for adequate fever or pain control 1
- Maximum daily limit: 534 mg total in 24 hours (60 mg/kg/day) 1
- Dosing interval: Every 6 hours, allowing up to 4 doses per day 1
Formulation and Administration
- Oral suspension concentration: Most pediatric acetaminophen suspensions are 160 mg/5 mL 2
- Volume calculation: For 10 mg/kg (89 mg), administer approximately 2.8 mL; for 15 mg/kg (134 mg), administer approximately 4.2 mL 2
- Administration: Can be given with or without food, though administration with meals may improve gastrointestinal tolerability 2
Critical Safety Considerations
- Avoid combination products: Parents must be counseled to avoid all other products containing acetaminophen, including over-the-counter cold remedies, as inadvertent overdosing is a significant risk 1
- Hepatotoxicity threshold: Toxicity is unlikely unless plasma concentrations exceed 150 micrograms/mL, far above therapeutic levels of 5-20 micrograms/mL 3
- No long-term hepatic damage: Long-term therapeutic use at recommended doses does not appear to be associated with liver damage 3
Common Pitfalls to Avoid
- Double-dosing error: The most common error is parents administering acetaminophen while also giving combination cold/flu products that contain acetaminophen 1
- Exceeding maximum daily dose: Never exceed 60 mg/kg/day (534 mg for this 8.9kg infant), as this increases hepatotoxicity risk 1
- Incorrect concentration: Verify the concentration of the suspension being used, as infant drops (80 mg/0.8 mL) differ from children's suspension (160 mg/5 mL) 2