Which antipyretic and dosing regimen is appropriate for a child older than three months and weighing at least 5 kg with persistent high fever despite acetaminophen (paracetamol), assuming no contraindications such as renal disease, dehydration, ulcer disease, or NSAID‑induced asthma?

Management of Persistent High Fever in Children Despite Paracetamol

For a child older than 3 months weighing at least 5 kg with persistent high fever despite paracetamol, ibuprofen 10 mg/kg every 6 hours (maximum 40 mg/kg/day) is the recommended next-step antipyretic. 1, 2

Ibuprofen Dosing and Administration

• Ibuprofen should be dosed at 10 mg/kg every 6 hours for optimal fever reduction in children who have not responded adequately to paracetamol 3
• The effective dose range is 7.5-10 mg/kg, with maximum temperature reduction occurring 3-4 hours after administration 4
• The maximum total daily dose is 30-40 mg/kg/day, divided into 3-4 doses 5
• Short-term use of ibuprofen is considered safe in infants older than 3 months with body weight above 5-6 kg when special attention is given to hydration 5

Key Safety Considerations

• Ensure adequate hydration before and during ibuprofen therapy, as dehydration significantly increases the risk of renal complications 5, 6
• Ibuprofen should be avoided in children with dehydration, renal disease, or active ulcer disease 1, 5
• Do not use ibuprofen in children with varicella (chickenpox) due to heightened risk of severe adverse events 1
• Ibuprofen is generally well-tolerated for short-term fever treatment in children with asthma, though monitoring for respiratory symptoms is advised 1

Comparative Efficacy

• Ibuprofen 10 mg/kg and paracetamol 15 mg/kg are equally effective after the initial dose, but ibuprofen has a longer duration of action 4, 3
• Clinical trials demonstrate that ibuprofen is equally effective as or more effective than paracetamol as an antipyretic 4
• There is no evidence that alternating ibuprofen with paracetamol provides superior benefit, and this practice increases the risk of dosing errors and toxicity 1

Treatment Goals and Monitoring

• The primary goal is to improve the child's overall comfort, not to normalize body temperature 1, 2
• Antipyretics do not prevent febrile seizures or reduce their recurrence risk 1, 2
• Encourage adequate fluid intake to maintain hydration and support the child's well-being 1
• Clinical improvement should occur within 48-72 hours; if no improvement or deterioration occurs, further investigation is required 1

Critical Pitfalls to Avoid

• Never use aspirin in children under 16-18 years due to the risk of Reye's syndrome, particularly with influenza or varicella 1
• Avoid ibuprofen in children with compromised fluid status, as even therapeutic doses of antipyretics can cause severe acute kidney injury in volume-depleted children 6
• Do not focus solely on temperature normalization—monitor the child's activity level, fluid intake, and signs of serious illness 2
• Ensure safe storage of antipyretics to prevent accidental poisoning 1