How frequently may ibuprofen be administered to an otherwise healthy 8‑year‑old child weighing 27 kg for fever?

Ibuprofen Dosing for Fever in an 8-Year-Old Child Weighing 27 kg

For an 8-year-old child weighing 27 kg with fever, administer ibuprofen 10 mg/kg per dose (270 mg), which can be repeated every 6–8 hours, with a maximum of 3–4 doses in 24 hours (not exceeding 30–40 mg/kg/day or approximately 810–1080 mg/day). 1

Weight-Based Dosing Algorithm

• The recommended single dose is 5–10 mg/kg, with 10 mg/kg being the most effective antipyretic dose for children 2, 1
• For a 27 kg child, this translates to:
  • Minimum effective dose: 135 mg (5 mg/kg)
  • Optimal antipyretic dose: 270 mg (10 mg/kg) 2, 3
• The effective dose range of 7.5–10 mg/kg has been validated in clinical trials, with maximum temperature reduction occurring 3–4 hours after administration 2

Dosing Frequency and Maximum Daily Limits

• Administer every 6–8 hours as needed for fever 1
• Maximum frequency: 3–4 times per day 1
• Maximum total daily dose: 30–40 mg/kg/day 1
  • For this 27 kg child: 810–1080 mg per 24 hours
• The pharmacokinetic half-life of ibuprofen in children is approximately 1.6 hours, supporting dosing intervals of 6–8 hours 4

Practical Administration Guidance

• Ibuprofen demonstrates linear dose-response kinetics in the 5–10 mg/kg range, meaning higher doses within this range provide greater antipyretic effect 2, 4
• Peak serum concentrations occur at approximately 1.1–1.2 hours after oral administration 4
• Maximum fever reduction is achieved 3–4 hours post-dose and ibuprofen has a longer duration of action compared to paracetamol 2

Critical Safety Considerations

• Hydration status must be adequate before and during ibuprofen administration, as this is the primary safety concern in pediatric use 1
• Ibuprofen is well-tolerated in children and safer in overdose than paracetamol or aspirin 2
• No adverse effects were observed in pharmacokinetic studies of children receiving 5–10 mg/kg doses 4
• When both paracetamol and ibuprofen are used together, carefully record all dose times to avoid accidentally exceeding maximum recommended doses (8% of children exceeded maximum paracetamol doses and 11% exceeded maximum ibuprofen doses in one study) 5

Comparative Effectiveness

• Ibuprofen is equally effective or more effective than paracetamol as an antipyretic, with superior fever-reducing effects demonstrated in African children 2, 3
• The proportion of afebrile children at 1.5–2.5 hours was significantly higher with ibuprofen (10 mg/kg) versus paracetamol (15 mg/kg) 3
• If using ibuprofen alone, it should be the first-line agent; combination therapy with paracetamol provides an additional 2.5 hours without fever over 24 hours but requires meticulous dose tracking 5

Common Pitfalls to Avoid

• Do not use the rectal route in young children, as absorption is erratic and unreliable 1
• Do not underdose: Using 5 mg/kg when 10 mg/kg is appropriate reduces antipyretic efficacy 2, 3
• Do not exceed 4 doses in 24 hours or the maximum daily dose of 40 mg/kg 1
• Ensure parents understand that fever is relatively short-lived (only 25% of children are "back to normal" by 48 hours), so prolonged use beyond 48 hours warrants medical re-evaluation 5