What is the appropriate Augmentin (amoxicillin‑clavulanate) dose for a 7‑year‑old child weighing 91 lb (41.3 kg) being treated for acute otitis media?

Augmentin Dosing for Acute Otitis Media

For this 7-year-old child weighing 41.3 kg with acute otitis media, prescribe Augmentin 90 mg/kg/day of amoxicillin component (3,717 mg/day total amoxicillin) divided into two doses given every 12 hours for 10 days.

Recommended Dosing Regimen

The appropriate dose is 1,858 mg of amoxicillin component twice daily, which translates to:

• Augmentin ES-600: 31 mL twice daily (if using the high-dose suspension)
• Standard high-dose formulation: Approximately 1,858 mg amoxicillin/264 mg clavulanate per dose

This provides the 90/6.4 mg/kg/day ratio (amoxicillin/clavulanate) recommended by current guidelines 1, 2.

Clinical Rationale

Why High-Dose Amoxicillin-Clavulanate?

High-dose amoxicillin-clavulanate is the first-line treatment for acute otitis media in children, particularly when:

• The child has received antibiotics within the past 30 days
• There is concurrent conjunctivitis (otitis-conjunctivitis syndrome)
• Coverage for β-lactamase-producing organisms (H. influenzae, M. catarrhalis) is needed
• There is concern for penicillin-resistant S. pneumoniae 1

The 2013 AAP guidelines explicitly recommend amoxicillin-clavulanate at 90 mg/kg/day of the amoxicillin component with 6.4 mg/kg/day of clavulanate, divided into 2 doses 1. This formulation achieves:

• 98.4% bacteriologic eradication of all S. pneumoniae strains
• 100% eradication of penicillin-resistant S. pneumoniae (MIC = 2 mcg/mL)
• 85.7% eradication of highly resistant S. pneumoniae (MIC = 4 mcg/mL)
• 92.6% eradication of H. influenzae
• 89.1% clinical success at 2-4 days post-therapy 2

Twice-Daily Dosing Advantage

Twice-daily dosing is preferred over three-times-daily because:

• Equivalent clinical efficacy (91.8% vs 90.5% success rates) 3
• Better compliance: 83.1% vs 72.8% adherence 3
• Lower diarrhea rates: 6.7% vs 10.3% protocol-defined diarrhea 3
• Reduced diaper dermatitis: 21% vs 33% 4

Treatment Duration

Prescribe for 10 days total 1, 2. This duration is standard for acute otitis media in children and was used in the pivotal efficacy trials demonstrating high bacteriologic and clinical cure rates.

Important Clinical Considerations

Common Pitfalls to Avoid

1. Do not underdose: The standard 40-45 mg/kg/day formulation is insufficient for resistant pathogens. The 90 mg/kg/day dose is critical for adequate coverage 1, 2.

2. Watch the clavulanate ratio: Use formulations with the 14:1 amoxicillin-to-clavulanate ratio (90/6.4 mg/kg/day), not older 7:1 ratios, to minimize gastrointestinal side effects while maintaining efficacy 1, 4.

3. Monitor for diarrhea: Protocol-defined diarrhea occurs in approximately 11-13% of patients on high-dose formulations 2. This is acceptable given the superior efficacy against resistant organisms.

When to Reassess

Clinical failure is defined as lack of improvement or worsening after 72 hours of therapy 2. If the patient fails to improve by 48-72 hours:

• Consider tympanocentesis if skilled in the procedure
• Switch to ceftriaxone 50 mg/kg IM/IV daily for 3 days 1
• Consider consultation with infectious disease or otolaryngology for persistent cases

Safety Profile

The high-dose formulation is well-tolerated with adverse events comparable to standard doses 2. Most common side effects include:

• Vomiting (6.5-6.9%)
• Fever (5.5-6.1%)
• Diaper rash/contact dermatitis (6.0-6.1%)
• Diarrhea (3.8-12.9%)

Only 2 patients per large trial required withdrawal due to diarrhea 2.