What is the appropriate ibuprofen dosage for a 7‑year‑old male weighing 46 kg?

Ibuprofen Dosing for a 7-Year-Old Male Weighing 46 kg

For this 7-year-old weighing 46 kg, administer ibuprofen 10 mg/kg per dose (460 mg) every 8 hours, with a maximum daily dose of 40 mg/kg/day (1,840 mg/day). 1, 2

Weight-Based Dosing Calculation

• The standard pediatric dose is 10 mg/kg per dose, which calculates to 460 mg for this 46 kg patient 1, 2, 3
• This patient exceeds 40 kg body weight, placing him at the upper end of pediatric weight-based dosing, but the 10 mg/kg calculation remains appropriate for children up to approximately 50 kg 2
• For practical administration, round to the nearest available tablet strength: 400-500 mg per dose is reasonable 2

Dosing Schedule and Maximum Limits

• Administer every 8 hours (3 times daily) with a maximum of 3 doses in 24 hours 1, 2, 3
• Maximum daily dose should not exceed 40 mg/kg/day, which equals approximately 1,840 mg/day for this patient 1, 2, 3
• The maximum single dose for children over 5 years is typically capped at 600 mg per dose, though this patient's calculated 460 mg dose falls comfortably below this threshold 3

Route of Administration

• Oral route is preferred for this age group and clinical scenario 1, 2, 3
• Avoid rectal administration as it has erratic absorption, particularly in younger patients, though this is less of a concern at age 7 4
• Intravenous ibuprofen (10 mg/kg every 8 hours) is reserved for postoperative or hospital settings and is not indicated for routine outpatient use 1

Clinical Pharmacology Considerations

• Peak effect occurs 3-4 hours after oral administration 5
• The elimination half-life in children is approximately 1.6 hours, supporting the every 8-hour dosing interval 6
• Pharmacokinetics are linear over the 5-10 mg/kg dose range and are not significantly affected by age in children 3-10 years old 6

Critical Safety Considerations

• Ensure adequate hydration before and during ibuprofen administration, as dehydration increases risk of renal complications 4
• Do not combine with other NSAID medications without dose adjustment to avoid inadvertent overdosing 2
• Be aware of "hidden sources" of NSAIDs in combination over-the-counter medications that parents may be administering 2
• Monitor for gastrointestinal symptoms, though ibuprofen is generally well-tolerated in children and safer in overdose than acetaminophen or aspirin 5

Common Pitfalls to Avoid

• Dosing based on age rather than weight is a frequent error that leads to under- or overdosing; always use weight-based calculations 7
• Parents commonly misdose antipyretics, with 51% giving inaccurate doses in one study; provide written dosing instructions with specific mg amounts and timing 7
• Caregivers who base dosing on weight are significantly less likely to misdose (RR 0.71), emphasizing the importance of clear weight-based education 7
• Exceeding the maximum recommended daily dose occurs in approximately 11% of children when parents are not given clear instructions about timing and maximum number of doses 8
• Provide parents with a dosing chart to record administration times to prevent accidental overdosing when using multiple antipyretics 8

Duration of Therapy

• Ibuprofen is intended for short-term use (typically 48-72 hours) for acute pain or fever management 4
• If fever or pain persists beyond 3 days, re-evaluation is warranted to assess for underlying conditions requiring different management 5