Acetaminophen Dosing for a 9-Year-Old Child
For a 9-year-old child, administer acetaminophen at 10-15 mg/kg per dose every 4-6 hours, not exceeding 60 mg/kg per day or 5 doses in 24 hours. 1
Weight-Based Dosing Approach
- The standard dose is 10-15 mg/kg per dose, with dosing intervals of 4-6 hours as recommended by the American Academy of Pediatrics 1
- The 15 mg/kg dose is more effective than 10 mg/kg, with studies showing that at least 10 mg/kg is required to maintain temperature reduction for 6 hours 2
- Pharmacokinetic modeling demonstrates that the 10 mg/kg dose may not reach therapeutic plasma concentrations (10-20 μg/mL) for optimal antipyresis, whereas 15 mg/kg is adequate 3
Maximum Daily Dose Limits
- Never exceed 60 mg/kg per day or 5 doses in 24 hours to prevent hepatotoxicity 1
- This maximum daily limit is critical for toxicity prevention and should be strictly observed 1
Practical Dosing Considerations
- Oral syrup formulation is preferred over rectal suppositories because it provides more rapid absorption and consistent response 1
- For a typical 9-year-old weighing approximately 25-35 kg, this translates to 250-525 mg per dose (using the 10-15 mg/kg range) 4, 5
- Clinical studies involving over 2,300 children confirm that the 10-15 mg/kg dose produces rapid onset of temperature reduction with maximum effect at approximately 3 hours post-administration 5
Important Caveats
- Weight-based dosing is superior to age-based dosing for accuracy, as age-based recommendations can lead to inadequate dosing in up to 30% of children 3
- The dose should be calculated based on the child's actual weight, not estimated or age-based approximations 4, 3
- Gastrointestinal adverse events are the most common side effects but are generally mild in intensity 5