What is the mid dose of Sugmentin (amoxicillin and clavulanic acid) for a 12-year-old boy weighing 35 kg?

Augmentin Dosing for a 12-Year-Old, 35 kg Child

For a 12-year-old child weighing 35 kg, the mid-dose of Augmentin 457 mg/5 mL suspension is 7.5 mL twice daily (providing approximately 68 mg/kg/day of amoxicillin), which falls between the standard dose of 45 mg/kg/day and the high dose of 90 mg/kg/day recommended for resistant pathogens. 1

Understanding Augmentin 457 mg/5 mL Formulation

• The Augmentin 457 mg/5 mL suspension contains 400 mg amoxicillin and 57 mg clavulanic acid per 5 mL, providing a 7:1 ratio designed to minimize gastrointestinal side effects while maintaining efficacy 2
• This formulation was specifically developed to provide higher amoxicillin doses without increasing clavulanic acid, which is associated with diarrhea 2

Dosing Algorithm Based on Infection Severity

For mild to moderate infections:

• Standard dose: 5 mL twice daily (45 mg/kg/day of amoxicillin component) 1
• This provides 1,575 mg amoxicillin per day for a 35 kg child
• Appropriate for uncomplicated skin infections, mild respiratory infections, or urinary tract infections 3

For moderate infections (mid-dose):

• Mid-dose: 7.5 mL twice daily (approximately 68 mg/kg/day of amoxicillin component)
• This provides 2,400 mg amoxicillin per day for a 35 kg child
• Reasonable for infections requiring more aggressive therapy but not meeting criteria for high-dose treatment

For severe infections or resistant pathogens:

• High dose: 10 mL twice daily (90 mg/kg/day of amoxicillin component) 4, 5
• This provides 3,150 mg amoxicillin per day for a 35 kg child
• Essential for community-acquired pneumonia, suspected penicillin-resistant Streptococcus pneumoniae, or β-lactamase-producing Haemophilus influenzae 6

Indication-Specific Recommendations

For community-acquired pneumonia:

• The Infectious Diseases Society of America recommends 90 mg/kg/day (10 mL twice daily) to overcome pneumococcal resistance 4, 5
• This high-dose regimen is critical because underdosing with 45 mg/kg/day is a common and dangerous error 5

For acute otitis media or sinusitis:

• High-dose therapy (90 mg/kg/day) is recommended when resistant S. pneumoniae is suspected 2
• The Centers for Disease Control and Prevention endorsed doubling amoxicillin doses due to increased nonsusceptible strains 2

For skin and soft tissue infections:

• Standard dose (45 mg/kg/day or 5 mL twice daily) is typically adequate for mild to moderate infections 3
• Consider high dose if Staphylococcus aureus is suspected 6

Critical Dosing Considerations

• Maximum daily dose: The absolute maximum is 4,000 mg/day of amoxicillin regardless of weight 1
• For this 35 kg child, even the high dose (3,150 mg/day) remains well below this maximum
• Timing: Administer at the start of meals to minimize gastrointestinal intolerance 3
• Duration: Continue for minimum 48-72 hours beyond symptom resolution 3
• For Streptococcus pyogenes infections, treat for at least 10 days to prevent acute rheumatic fever 3

Common Pitfalls to Avoid

• Underdosing for pneumonia: Using 45 mg/kg/day instead of the recommended 90 mg/kg/day for community-acquired pneumonia is a critical error that may lead to treatment failure 5
• Incorrect formulation selection: Ensure you're using the 457 mg/5 mL (ES-600 equivalent) formulation, not the older 250 mg/5 mL or 125 mg/5 mL suspensions 2
• Inadequate treatment duration: Stopping antibiotics when symptoms improve rather than completing the full course increases resistance risk 3
• Ignoring renal function: Although this child likely has normal renal function, always verify, as severe renal impairment requires dose adjustment 3

Practical Administration

• Shake the suspension vigorously before each dose 3
• Store reconstituted suspension in refrigerator (preferred but not required) 3
• Discard any unused portion after 14 days 3
• The suspension can be mixed with formula, milk, or juice if needed, but must be consumed immediately 3

When to Reassess or Escalate

• If no clinical improvement occurs within 48-72 hours, consider treatment failure and reassess for complications or alternative diagnoses 5
• For severe pneumonia with suspected MRSA (necrotizing infiltrates, empyema, post-influenza), add vancomycin or clindamycin 5
• Obtain cultures before changing antibiotics if possible 5