Ibuprofen (Motrin) Dosing for Your 4-Year-Old
Give your child 160 mg of ibuprofen (Motrin) every 6-8 hours as needed for fever or pain, which you can repeat up to 3-4 times in 24 hours. 1, 2
Dose Calculation
Your 4-year-old weighs 35 lbs (approximately 16 kg). The recommended dose is:
- Standard dose: 10 mg/kg per dose 1, 3, 2
- For your child: 10 mg/kg × 16 kg = 160 mg per dose 1
- Dosing interval: Every 6-8 hours 1, 2
- Maximum frequency: 3-4 doses in 24 hours 1, 2
- Maximum daily dose: 30-40 mg/kg/day (480-640 mg/day for your child) 2
Practical Administration
- Use weight-based dosing, not age-based dosing - Parents who dose by weight are significantly less likely to give incorrect doses 4
- Measure with the dosing device that comes with the medication - Never use household spoons 4
- Write down each dose time to avoid accidentally exceeding the maximum recommended doses, which occurs in 11% of children 3
Expected Response
- Peak effect occurs 3-4 hours after administration 5
- Duration of action: 6-8 hours 1, 5
- Ibuprofen provides longer fever control than acetaminophen and is equally or more effective 5
Critical Safety Points
- Ensure adequate hydration - Give plenty of fluids while using ibuprofen 2
- Do not give more frequently than every 6 hours to prevent overdosing 1, 2
- Avoid if your child has dehydration, kidney problems, or active bleeding 2
- Do not combine with aspirin - Ibuprofen should not be given within 4 hours of aspirin 1
When to Consider Medical Evaluation
- Fever persists beyond 48 hours despite appropriate dosing 3
- Child appears severely ill or has difficulty breathing 3
- Signs of dehydration develop (decreased urination, dry mouth, lethargy) 2
- Fever is higher than 104°F (40°C) 3
Common Pitfall to Avoid
The most common dosing error is using age instead of weight - 51% of parents give inaccurate doses, with infants at highest risk for dosing errors 4. Always calculate the dose based on your child's actual weight in kilograms (divide pounds by 2.2) 4.