What is the recommended dosage of ibuprofen (Nonsteroidal Anti-Inflammatory Drug) and acetaminophen (paracetamol) for managing fever in adults and pediatric patients?

Recommended Dosages of Ibuprofen and Acetaminophen for Fever Management in Adults and Children

For fever management in adults, acetaminophen should be dosed at 650-1000 mg every 6 hours (maximum 4000 mg daily) while ibuprofen should be dosed at 400 mg every 6-8 hours (maximum 2400 mg daily). For children, acetaminophen should be dosed at 10-15 mg/kg every 6 hours and ibuprofen at 10 mg/kg every 6-8 hours. 1

Adult Dosing

Acetaminophen (Paracetamol)

• Standard dose: 650-1000 mg every 6 hours
• Maximum daily dose: 4000 mg
• Duration: Use for shortest duration needed to control symptoms

Ibuprofen

• Standard dose: 400 mg every 6-8 hours
• Maximum daily dose: 2400 mg
• Duration: Use for shortest duration needed to control symptoms

Pediatric Dosing

Acetaminophen (Paracetamol)

• Oral dosing: 10-15 mg/kg every 6 hours (maximum daily dose: 60 mg/kg) 2
• Intravenous dosing (when oral not possible):
  • Loading dose: 15-20 mg/kg
  • Maintenance: 10-15 mg/kg every 6-8 hours 2

Ibuprofen

• Oral dosing: 10 mg/kg every 8 hours 2, 3
• Rectal dosing: 10 mg/kg every 8 hours 2

Comparative Efficacy

Research shows that ibuprofen is slightly more effective than acetaminophen for fever reduction:

• Ibuprofen (5-10 mg/kg) reduces temperature more effectively than acetaminophen (10-15 mg/kg) at 2,4, and 6 hours after treatment 4
• For adults with fever ≥38.1°C, ibuprofen 400 mg can reduce temperature by approximately 0.76°C after 4 hours 5

Special Populations

Elderly (≥65 years)

• No specific dose reduction needed for acetaminophen or ibuprofen based on age alone 2
• Consider lower doses in patients with renal impairment

Patients with Comorbidities

• Liver disease: Prefer acetaminophen at standard doses 1
• Gastrointestinal concerns: Prefer acetaminophen 1
• Cardiovascular disease: Consider acetaminophen first 1
• Renal impairment: Use caution with NSAIDs; consider acetaminophen

Combination Therapy

In children with fever, using both medications together provides:

• Additional time without fever in the first 24 hours compared to either medication alone 6
• However, careful recording of dosing times is essential to avoid exceeding maximum recommended doses 6

Safety Considerations

• Both medications have similar safety profiles when used at recommended doses 4
• Avoid exceeding recommended maximum daily doses
• For children, avoid aspirin due to risk of Reye syndrome 1
• Monitor for potential adverse effects:
  • Acetaminophen: Hepatotoxicity at high doses
  • Ibuprofen: Gastrointestinal irritation, renal effects

Practical Recommendations

1. For most patients, either medication is appropriate first-line therapy
2. For faster or more effective fever reduction, particularly in children, ibuprofen may be preferred
3. For patients with contraindications to NSAIDs (gastrointestinal ulcers, renal impairment, certain cardiovascular conditions), use acetaminophen
4. When using both medications in alternating schedules, maintain careful records of administration times to prevent overdosing

Both medications are effective for managing fever, with the choice depending on patient-specific factors including comorbidities, contraindications, and previous response to treatment.