In otherwise healthy pediatric patients, which antipyretic—acetaminophen (paracetamol) or ibuprofen—is more effective for fever reduction?

Ibuprofen vs Acetaminophen for Pediatric Fever Management

Ibuprofen is more effective than acetaminophen for fever reduction in otherwise healthy pediatric patients, though acetaminophen remains the recommended first-line agent by the American Academy of Pediatrics due to its superior safety profile.

Guideline-Based First-Line Recommendation

• The American Academy of Pediatrics recommends acetaminophen as first-line pharmacologic antipyretic therapy (10-15 mg/kg every 4-6 hours, maximum 5 doses per 24 hours) due to its relative safety and effectiveness 1
• Acetaminophen has a better safety profile compared to NSAIDs regarding gastrointestinal and cardiovascular effects 1
• The primary goal of fever treatment should be improving the child's overall comfort rather than normalizing body temperature 1, 2

Comparative Efficacy: Ibuprofen Shows Superior Antipyretic Effect

Despite guideline preference for acetaminophen, the evidence demonstrates ibuprofen's superior fever-reducing capability:

Temperature Reduction at Different Time Points

• At 1-2 hours post-administration: No significant difference between the two medications 3, 4
• At 4-6 hours post-administration: Ibuprofen demonstrates clear superiority
  • Mean temperature reduction 0.58°C lower with ibuprofen compared to acetaminophen at 6 hours 3
  • Effect sizes at 2,4, and 6 hours favor ibuprofen (5-10 mg/kg) over acetaminophen (10-15 mg/kg): 0.19,0.31, and 0.33 respectively 4
  • In children under 2 years, ibuprofen resulted in reduced temperature at both <4 hours and 4-24 hours compared to acetaminophen 5

Pain Relief

• For moderate to severe pain, single doses of ibuprofen (4-10 mg/kg) and acetaminophen (7-15 mg/kg) show similar efficacy 4
• At 4-24 hours, ibuprofen provides slightly better pain control in young children (effect size 0.20) 5

Safety Profile: Equivalent in Short-Term Use

Both medications demonstrate comparable safety in otherwise healthy children:

• No evidence of difference in short-term adverse effects between the two drugs 3, 2
• Serious adverse event profiles appear similar (odds ratio 1.08,95% CI 0.87-1.33) 5
• Both are well-tolerated for fever management in healthy pediatric patients 4

Important Safety Caveats and Contraindications

Acetaminophen-Specific Concerns

• Risk of hepatotoxicity at doses only slightly above therapeutic levels 1
• Caution in chronic alcohol use or liver disease 1
• Present in many combination products, increasing overdose risk 1

Ibuprofen-Specific Concerns

• Risks of respiratory failure, metabolic acidosis, and renal failure in overdose or with risk factors 1
• Caution in patients >60 years or with compromised fluid status/renal insufficiency 1
• Should not be used in Kawasaki disease patients taking aspirin (antagonizes antiplatelet effect) 1
• Generally safe in children with asthma when following standard contraindications, though monitor for respiratory symptoms 1

Universal Contraindications

• Aspirin should be avoided in children under 16-18 years due to Reye's syndrome risk 1

Alternating Therapy: Not Recommended

• While some evidence suggests alternating acetaminophen and ibuprofen may be more effective than monotherapy 6, the American Academy of Pediatrics does not recommend this approach 1
• Concerns include increased risk of dosing errors and toxicity 1
• The added complexity outweighs potential benefits in routine practice 1, 2

Clinical Pearls

• Antipyretics do NOT prevent febrile seizures or reduce their recurrence risk 1, 7, 2
• Encourage adequate fluid intake as crucial for child well-being 1
• Emphasize safe storage to prevent accidental poisonings 1
• Monitor for clinical improvement within 48-72 hours; investigate further if no improvement 1

Practical Algorithm

For otherwise healthy febrile children:

1. Start with acetaminophen (10-15 mg/kg every 4-6 hours) as first-line per AAP guidelines 1
2. Consider ibuprofen (5-10 mg/kg every 6-8 hours) if:
   • Longer duration of action is desired (ibuprofen's effect lasts longer) 3
   • Acetaminophen provides inadequate fever control
   • No contraindications to NSAID use exist 1
3. Avoid alternating regimens due to dosing complexity and safety concerns 1
4. Focus on comfort rather than temperature normalization 1, 2