Motrin (Ibuprofen) Dosing for a 47-Pound Child
For a 47-pound (21.3 kg) child, give 213 mg of ibuprofen per dose, administered every 6-8 hours, with a maximum of 3 doses in 24 hours. 1
Weight-Based Calculation
- The standard pediatric dose is 10 mg/kg per dose 1, 2
- For a 47-pound child (21.3 kg): 10 mg/kg × 21.3 kg = 213 mg per dose 1
- This dose can be repeated every 6-8 hours as needed 1
- Maximum daily dose is 40 mg/kg/day (approximately 850 mg/day for this child) 2
Practical Administration
- Round to the nearest measurable dose based on available formulations (typically 200 mg or 220 mg would be appropriate) 1
- The effective dose range is 7.5-10 mg/kg, so slight variations are acceptable 3
- Maximum reduction in temperature occurs 3-4 hours after administration 3
Important Safety Considerations
- Do not exceed 3 doses in 24 hours 1
- Ibuprofen should not be used in infants under 6 months of age 1
- For this weight (47 pounds/21.3 kg), the child is well above the minimum age and weight requirements 1
Comparison to Acetaminophen
- Ibuprofen has a longer duration of action (6-8 hours) compared to acetaminophen (4-6 hours) 1
- Ibuprofen may be more effective than acetaminophen as an antipyretic, with an additional 2.5 hours without fever over 24 hours 4
- Ibuprofen should be considered as first-line treatment for fever in children who can tolerate it 4
Common Pitfalls to Avoid
- Parents frequently misdose antipyretics, with 51% giving inaccurate doses in one study 5
- Weight-based dosing is more accurate than age-based dosing - caregivers who dosed by weight were less likely to make errors 5
- Always record dose times carefully to avoid accidentally exceeding the maximum recommended dose 4