What is the recommended dose of Augmentin (amoxicillin-clavulanate) for a 13-year-old male patient weighing 122 pounds with normal kidney function and no known allergies to penicillin or other beta-lactam antibiotics?

Augmentin Dosing for a 13-Year-Old Male Weighing 122 lbs

For a 13-year-old male weighing 122 lbs (55.4 kg), the recommended Augmentin dose is 500 mg twice daily for mild-to-moderate infections or 875 mg twice daily for severe infections, treating this patient as an adult given the weight exceeds 40 kg. 1, 2

Weight-Based Dosing Threshold

• At 122 lbs (55.4 kg), this patient exceeds the 40 kg (88 lb) threshold where pediatric weight-based dosing transitions to standard adult dosing. 1, 2
• The American Academy of Pediatrics recommends weight-based formulas (mg/kg) only for children under 40 kg, and this patient clearly exceeds that cutoff. 3, 2

Standard Adult Dosing Regimen

For mild-to-moderate infections:

• Augmentin 500 mg (amoxicillin component) twice daily for 10 days 4
• This provides approximately 18 mg/kg/day of amoxicillin, which is appropriate for standard infections 1

For severe infections or lower respiratory tract infections:

• Augmentin 875 mg twice daily for 10 days 1
• This provides approximately 32 mg/kg/day of amoxicillin, addressing more resistant organisms 5

Infection-Specific Considerations

For Group A streptococcal pharyngitis (if treating chronic carriers):

• Augmentin 40 mg amoxicillin per kg per day in three divided doses (maximum 2,000 mg amoxicillin per day) for 10 days 4
• For this 55.4 kg patient, this would be approximately 2,000 mg/day divided into three doses (approximately 667 mg three times daily) 4

For acute otitis media or recurrent infections:

• High-dose amoxicillin/clavulanate may be considered, providing 80-90 mg/kg/day of the amoxicillin component 5
• However, at this weight, standard adult dosing of 875 mg twice daily is typically sufficient 1

Critical Dosing Principles

• Always calculate based on actual body weight in kilograms (122 lbs = 55.4 kg) 2
• Never round to convenient tablet strengths without ensuring the dose falls within the appropriate mg/kg range 2
• Standard treatment duration is 10 days for most infections 4

Common Pitfall to Avoid

The main error would be continuing to use pediatric weight-based dosing for this patient. At 55.4 kg, this adolescent should receive standard adult dosing rather than calculating mg/kg doses, as the weight far exceeds the 40 kg pediatric threshold. 3, 1, 2