Naproxen Dosing for an 82-Pound Child
For a child weighing 82 pounds (37 kg), prescribe naproxen 5-7.5 mg/kg every 12 hours, which translates to 185-280 mg twice daily.
Weight-Based Dosing Calculation
The child weighs 82 pounds (37.2 kg), placing them in the standard pediatric dosing range where weight-based calculations apply:
- Standard pediatric dose: 5-7.5 mg/kg every 12 hours 1
- For 37 kg: 185-280 mg twice daily
- Practical dosing: Start with 200-250 mg twice daily (every 12 hours)
Key Dosing Principles
Maximum daily dose considerations:
- Total daily dose should not exceed 15 mg/kg/day 2, 3
- For this 37 kg child: maximum 555 mg/day total
- This allows for 250 mg twice daily (500 mg/day) safely within limits
Formulation selection: The FDA-approved naproxen suspension is ideal for pediatric patients, as it allows precise weight-based dosing 2. If using tablets, the 250 mg strength provides appropriate dosing flexibility for this weight range.
Age and Safety Considerations
Naproxen is FDA-approved for children ≥2 years of age 2. The evidence base supports:
- Efficacy: Well-established in juvenile arthritis at 10-20 mg/kg/day divided doses 4, 5, 6
- Pharmacokinetics: Weight-based dosing is appropriate for children >3 months, as clearance scales predictably with body weight 3
- Safety profile: Generally well-tolerated with fewer gastrointestinal side effects compared to aspirin in pediatric populations 6
Clinical Monitoring
Monitor for:
- Gastrointestinal symptoms (most common adverse effect)
- Adequate pain relief within 1 hour of first dose 2
- Renal function if prolonged use (>5-7 days)
Important caveat: Use the lowest effective dose for the shortest duration needed 2. For acute pain conditions, reassess after 2-3 days. If treating chronic conditions like juvenile arthritis, doses up to 10-15 mg/kg/day may be appropriate with close monitoring 4, 6.
The 82-pound weight places this child above the typical cutoff where adult dosing might be considered (≥40 kg or 88 pounds), but they remain just below this threshold, making weight-based pediatric dosing most appropriate 1, 7.