Is 9.5 mL of ibuprofen (IBU) 100 mg/5 mL an appropriate dose for a pediatric patient who is 3 years and 7 months old and weighs 19 kg?

Ibuprofen Dosing Assessment for 3-Year-7-Month-Old, 19 kg Child

No, 9.5 mL of ibuprofen 100 mg/5 mL (190 mg total) is excessive and potentially unsafe for this child—the appropriate dose should be 7.5-9.5 mL maximum (150-190 mg), with 7.5 mL (150 mg) being the safer target dose.

Dose Calculation and Safety Analysis

Standard Pediatric Ibuprofen Dosing

• The recommended dose for children is 5-10 mg/kg per dose, given every 6-8 hours, with a maximum of 40 mg/kg/day 1, 2
• For this 19 kg child:
  • Minimum therapeutic dose: 95 mg (5 mg/kg × 19 kg = 4.75 mL)
  • Standard therapeutic dose: 150 mg (approximately 8 mg/kg = 7.5 mL)
  • Maximum single dose: 190 mg (10 mg/kg × 19 kg = 9.5 mL)
  • Maximum daily dose: 760 mg (40 mg/kg/day) 1

Critical Assessment of 9.5 mL Dose

• 9.5 mL delivers 190 mg of ibuprofen (100 mg/5 mL × 9.5 = 190 mg) 1
• This represents exactly 10 mg/kg, which is at the absolute upper limit of single-dose recommendations 1, 2
• While technically within range, this dose provides no safety margin and increases risk of adverse effects, particularly with repeated dosing 1, 2

Age-Appropriate Dosing Considerations

Developmental Pharmacology

• Children aged 2 years and older are pharmacologically mature and differ from adults primarily in size, not drug metabolism 3, 4
• At 3 years 7 months, this child has mature drug elimination pathways, unlike neonates and infants who require special consideration 3, 4
• For children in this age range (1-5 years), weight-based dosing normalized to body surface area is most appropriate 4

Practical Dosing Recommendation

• The optimal dose for this child is 7.5 mL (150 mg), which provides 7.9 mg/kg—a therapeutically effective dose with an appropriate safety margin 1, 2
• If stronger analgesia is needed, 8.5-9 mL (170-180 mg) represents a reasonable middle ground 1
• Reserve the 9.5 mL dose only for severe pain or fever unresponsive to lower doses 1, 2

Safety Profile and Adverse Effects

Dose-Dependent Risks

• Adverse reactions to ibuprofen are dose and duration dependent 2
• At OTC doses (typically 5-7 mg/kg), ibuprofen has excellent tolerability comparable to acetaminophen 1, 2
• Higher doses approaching 10 mg/kg increase risk of gastrointestinal, renal, and hepatic adverse effects 1, 2

Pediatric-Specific Safety

• Ibuprofen is relatively safe and effective for acute pain and fever in children, with lower risk of serious adverse events compared to other NSAIDs 1
• The short plasma half-life and lack of toxic metabolites contribute to its favorable safety profile 1
• However, exceeding recommended doses increases risk even in children 1, 2

Common Pitfalls to Avoid

• Do not automatically use the maximum dose (10 mg/kg) as the standard dose—start with 5-8 mg/kg and escalate only if needed 1, 2
• Ensure proper dosing interval (every 6-8 hours) to avoid exceeding maximum daily dose of 40 mg/kg/day 1
• Verify the concentration of the suspension—errors in concentration interpretation are a common source of dosing mistakes 4
• Consider using 7.5 mL as the standard dose rather than rounding up to 9.5 mL, as this provides adequate analgesia with better safety margin 1, 2