What is the appropriate oral dose of Augmentin (amoxicillin-clavulanate) for a 12-year-old patient weighing 31kg?

Oral Augmentin Dosing for a 12-Year-Old Weighing 31kg

For a 12-year-old patient weighing 31kg, the appropriate dose of oral Augmentin depends on the indication: for mild to moderate infections, administer 45 mg/kg/day of the amoxicillin component divided into 2 doses (approximately 700 mg twice daily), while for severe respiratory infections or suspected resistant pathogens, use 90 mg/kg/day divided into 2 doses (approximately 1,400 mg twice daily). 1, 2

Standard Dosing Framework

Weight-based calculation for this patient:

• Standard dose (45 mg/kg/day): 31 kg × 45 mg/kg = 1,395 mg/day total, divided as ~700 mg twice daily 1, 3
• High dose (90 mg/kg/day): 31 kg × 90 mg/kg = 2,790 mg/day total, divided as ~1,400 mg twice daily 1, 2

The FDA label confirms that pediatric patients aged 12 weeks and older should receive either 25 mg/kg/day every 12 hours for less severe infections or 45 mg/kg/day every 12 hours for otitis media, sinusitis, lower respiratory tract infections, and more severe infections. 3

Indication-Specific Dosing Recommendations

For community-acquired pneumonia or suspected resistant pathogens:

• The Infectious Diseases Society of America recommends 90 mg/kg/day of the amoxicillin component divided into 2 doses for presumed bacterial pneumonia, particularly when penicillin-resistant Streptococcus pneumoniae or β-lactamase-producing Haemophilus influenzae are suspected. 4, 1
• This high-dose regimen provides optimal coverage and maintains therapeutic concentrations against resistant organisms. 1, 2

For less severe respiratory infections or skin/soft tissue infections:

• The standard dose of 45 mg/kg/day divided into 2 doses is appropriate. 1, 3

For β-lactamase-producing H. influenzae:

• The Infectious Diseases Society of America recommends either 45 mg/kg/day in 3 doses OR 90 mg/kg/day in 2 doses of the amoxicillin component. 4, 1

Practical Formulation Selection

For this 31kg patient, appropriate formulations include:

• Oral suspension: Use the 400 mg/5 mL formulation for easier dosing in this weight range. 3
• Tablets: Since the patient weighs less than 40 kg, use chewable tablets (250 mg/62.5 mg formulation) rather than adult tablets (250 mg/125 mg), as these contain different ratios of clavulanic acid and are not interchangeable. 3

The American Academy of Pediatrics emphasizes that the maximum daily dose should not exceed 4,000 mg (4 g) of amoxicillin per day, regardless of weight. 1, 2

Treatment Duration and Monitoring

Standard treatment duration:

• Most respiratory infections require 7-10 days of therapy. 1
• Pneumonia specifically requires 10 days of treatment. 1

Expected clinical response:

• Children on appropriate antibiotic therapy should demonstrate clinical improvement within 48-72 hours. 1
• If no improvement occurs within this timeframe, reevaluation and consideration of atypical pathogens or treatment failure is necessary. 1

Critical Considerations and Common Pitfalls

Avoid these common errors:

• Do not substitute two 250 mg/125 mg tablets for one 500 mg/125 mg tablet, as they contain the same amount of clavulanic acid (125 mg) but different amounts of amoxicillin. 3
• Do not use the 250 mg/125 mg adult tablets until the child weighs at least 40 kg, due to different amoxicillin-to-clavulanic acid ratios. 3
• Do not underdose for severe infections—use the full 90 mg/kg/day regimen when resistant pathogens are suspected, particularly in areas with high pneumococcal resistance or in patients with recent antibiotic exposure within the past 3 months. 1, 2

Special circumstances requiring high-dose therapy:

• Recent antibiotic use within the past 4-6 weeks 1
• Daycare attendance 1
• Geographic areas with high rates of penicillin-resistant S. pneumoniae 1, 2
• Treatment failure on standard-dose amoxicillin 1

The American Academy of Pediatrics notes that twice-daily dosing is preferred over three-times-daily dosing for improved adherence and comparable efficacy, with significantly less diarrhea. 3