What is the recommended oral dose of Motrin (ibuprofen) for a 10-year-old patient weighing 30-40 kilograms?

Motrin (Ibuprofen) Dosing for a 10-Year-Old

For a 10-year-old child, administer ibuprofen at 10 mg/kg per dose orally every 6-8 hours, with a maximum single dose of 600 mg and a maximum daily dose of 40 mg/kg/day (not exceeding 2400 mg/day). 1

Weight-Based Dosing Calculation

• For a 30 kg child: 300 mg per dose (10 mg/kg), administered every 6-8 hours 1, 2
• For a 40 kg child: 400 mg per dose (10 mg/kg), administered every 6-8 hours 1, 2
• Maximum single dose: 600 mg regardless of weight 1
• Maximum daily dose: 40 mg/kg/day or 2400 mg/day, whichever is lower 1, 2

Dosing Frequency and Duration

• Standard dosing interval: Every 6-8 hours (3-4 times daily) 1, 2
• Minimum interval between doses: 6 hours to avoid exceeding maximum daily limits 2
• Duration of action: Peak fever reduction occurs at 3-4 hours after administration 3

Clinical Efficacy Considerations

• The effective dose range for fever and pain control in children is 7.5-10 mg/kg per dose 3
• 10 mg/kg dosing is more effective than lower doses (5 mg/kg) for initial fever reduction, though differences diminish after the second dose 4
• Ibuprofen has a longer duration of antipyretic action compared to acetaminophen, providing approximately 2.5 additional hours without fever over 24 hours 5

Safety Profile

• Short-term use is considered safe in children over 3 months of age with body weight above 5-6 kg when adequate hydration is maintained 2
• Ibuprofen is better tolerated in children than adults and safer in overdose than acetaminophen 3
• The pharmacokinetics are linear over the 5-10 mg/kg dose range, with an elimination half-life of approximately 1.6 hours 6

Important Clinical Caveats

• Ensure adequate hydration before and during ibuprofen administration, as this is critical for safety in the pediatric population 2
• Avoid rectal administration in young patients due to erratic absorption 2
• Do not exceed 4 doses in 24 hours when using every 6-hour dosing, or 3 doses when using every 8-hour dosing 1, 2
• Parents should carefully record all dose times to prevent inadvertently exceeding maximum recommended doses, which occurred in 8% of children in clinical trials 5

Administration Recommendations

• Administer with food if gastrointestinal upset occurs, though this may slightly delay absorption 5
• Use weight-based dosing rather than age-based dosing for optimal efficacy and safety 1, 2
• For children weighing >40 kg, adult dosing may be appropriate (typically 400-600 mg per dose) 1