Acetaminophen Dosing for a 70lb (31.8kg) 11-Year-Old Child
The recommended acetaminophen dosage for an 11-year-old child weighing 70 pounds (31.8 kg) is 480 mg (15 mg/kg) every 4-6 hours as needed, not to exceed 5 doses (2400 mg) in 24 hours.
Weight-Based Dosing Calculation
- For children, acetaminophen should be dosed at 10-15 mg/kg per dose 1
- At 15 mg/kg (the higher end of the therapeutic range for better efficacy), a 31.8 kg child should receive 477 mg, which can be rounded to 480 mg 1, 2
- Lower doses of 10 mg/kg may not reach therapeutic plasma concentrations for effective fever reduction 3
Administration Guidelines
- For an 11-year-old weighing 70 pounds (31.8 kg), appropriate dosing options include:
- Maximum frequency: Every 4-6 hours as needed 1
- Maximum daily dose: Do not exceed 5 doses (2400 mg) in 24 hours 5
Important Considerations
- Weight-based dosing is more accurate than age-based dosing and reduces the risk of medication errors 6
- Studies show that up to 51% of caregivers give inaccurate doses of acetaminophen, with underdosing being a common issue 6
- The 15 mg/kg dose is preferred over 10 mg/kg as pharmacokinetic modeling shows the lower dose may not reach therapeutic plasma concentrations (10-20 μg/mL) needed for effective fever reduction 3
Safety Precautions
- Use appropriate measuring devices for liquid formulations if tablets are not used 4
- Do not exceed the maximum daily dose to avoid potential hepatotoxicity 1
- Single ingestions of more than ten times the recommended dose (>150 mg/kg) are potentially toxic 1
- For children weighing over 40 kg, adult dosing guidelines may be applied, but this child at 31.8 kg should still receive pediatric weight-based dosing 4