Naproxen Dosing for a 13-Year-Old
For a 13-year-old patient, the recommended dosage of naproxen is 5 mg/kg twice daily, not to exceed 500 mg per dose or 1000 mg per day total.
Weight-Based Dosing Considerations
The appropriate naproxen dosage for a 13-year-old depends primarily on their weight:
If the 13-year-old weighs more than 40 kg (88 lb):
If the 13-year-old weighs less than 40 kg:
- Dosing should be weight-based at approximately 5 mg/kg twice daily 2
- This is equivalent to approximately 10 mg/kg/day total divided into two doses
Formulation Options
Naproxen is available in several formulations:
- Tablets (250 mg, 375 mg, 500 mg)
- Oral suspension (more appropriate for precise weight-based dosing)
- Delayed-release tablets
- Naproxen sodium tablets
Note that different formulations are not necessarily bioequivalent, which should be considered when selecting the appropriate form 1.
Duration of Treatment
- For acute pain conditions: Short-term use (3-5 days) is recommended
- For chronic conditions like juvenile arthritis: Longer-term use may be necessary, but should include regular monitoring for adverse effects 3
Safety Considerations
Potential Adverse Effects
- Gastrointestinal effects: Risk of gastroduodenal ulcers is lower than with some other NSAIDs but still present 4
- Renal effects: Caution in patients with any degree of renal impairment
- Cardiovascular effects: Monitor for hypertension with prolonged use
Important Precautions
- Should be taken with food to minimize gastrointestinal irritation
- Maintain adequate hydration during treatment
- Start with the lowest effective dose and titrate as needed
- Treatment for non-chronic conditions should be kept as short as possible 3
Clinical Pearls
- Once or twice daily dosing is convenient for adolescents
- Naproxen has a longer half-life than ibuprofen, allowing for less frequent dosing
- For treatment of juvenile arthritis, naproxen has demonstrated comparable efficacy to other NSAIDs 2
- Treatment should be initiated with the lowest age-appropriate or weight-based dose to improve safety profile 3
Always monitor for signs of adverse effects, particularly with extended use, and discontinue if significant side effects occur.