Tylenol (Acetaminophen) Dosing for Infants
For infants, give acetaminophen 10-15 mg/kg per dose every 4-6 hours, with a maximum of 60 mg/kg per day or 5 doses in 24 hours. 1
Age-Specific Dosing Guidelines
Infants Under 3 Months
- Acetaminophen is the only recommended analgesic for this age group 1
- Use 15 mg/kg per dose if weight is less than 10 kg 1
- Dosing interval: every 4-6 hours 1
- Important caveat: There are limited formal guidelines for neonates under 1 month, though 30 mg/kg/day achieves effective therapeutic concentrations in this population 2
Infants 3 Months and Older
- Standard dose: 10-15 mg/kg per dose 1, 3
- Frequency: every 4-6 hours 1
- The 15 mg/kg dose is more effective than 10 mg/kg and is necessary to maintain adequate fever reduction for 6 hours 4, 5
Critical Safety Limits
- Never exceed 60 mg/kg per day total 1
- Never give more than 5 doses in 24 hours 1
- The 10 mg/kg dose may not reach therapeutic plasma concentrations (10-20 μg/mL) needed for effective antipyresis, whereas 15 mg/kg is adequate 5
Formulation Considerations
Oral vs. Rectal Administration
- Oral syrup is preferred because it is absorbed more rapidly and provides more consistent response compared to suppositories 1
- Rectal acetaminophen should be used cautiously due to erratic absorption 1
- Some children may receive inadequate analgesia with rectal formulations while others risk accumulation with repeated dosing 1
- Rectal administration can be considered for actively vomiting children or perioperative situations where oral intake is restricted 1
Common Pitfalls to Avoid
Age-based dosing errors are extremely common - up to 30% of febrile children receive inadequate doses at home, primarily due to reliance on age rather than weight-based dosing 5. The manufacturer's suggested dose of 160 mg for children aged 2-3 years is only effective for children weighing exactly 10.9 kg, and underdoses heavier children in this age range 5.
Always use weight-based dosing (mg/kg) rather than age-based recommendations to ensure adequate therapeutic effect 5.