Acetaminophen Dosing for a 6-Year-Old with Fever
For a 6-year-old child with fever, administer acetaminophen 15 mg/kg every 4-6 hours, not to exceed 5 doses in 24 hours or a maximum daily dose of 75 mg/kg/day (approximately 60-75 mg/kg/day). 1
Weight-Based Dosing Algorithm
- The optimal single dose is 15 mg/kg, which provides adequate plasma concentrations for antipyresis (10-20 μg/mL) 2, 3
- Doses can be repeated every 4-6 hours as needed 1, 2
- Do not exceed 5 doses in 24 hours 4
- The maximum daily dose should not exceed 75 mg/kg/day (some sources cite 60 mg/kg/day as the upper limit) 4
Practical Calculation
For a typical 6-year-old weighing approximately 20 kg:
- Single dose: 300 mg (15 mg/kg × 20 kg) 2
- This can be given every 4-6 hours 1, 2
- Maximum daily dose: 1200-1500 mg 4
Important Caveats
- The 10 mg/kg dose is inadequate: Pharmacokinetic modeling demonstrates that 10 mg/kg fails to reach therapeutic plasma concentrations (10-20 μg/mL) needed for effective antipyresis 3
- Age-based dosing leads to errors: Up to 30% of children receive inadequate doses when parents use age-based rather than weight-based dosing 3
- Avoid chronic overdosing: Exposures greater than 140 mg/kg/day for several days carry risk of serious hepatotoxicity 4
Alternative: Ibuprofen
- Ibuprofen 10 mg/kg every 6 hours can be used as an alternative or in combination with acetaminophen 1
- For a 20 kg child: 200 mg every 6 hours 1
- Ibuprofen remains second-line to acetaminophen in pediatric fever management 4
Special Considerations for Children with Seizure History
- For children with a history of febrile seizures or convulsions, acetaminophen 15 mg/kg should be given every 4 hours for 24 hours following vaccination or during febrile illness to reduce the possibility of fever-induced seizures 5