What is the appropriate dosage of Augmentin (amoxicillin/clavulanate) for a 3-year-old, 22kg child with bacterial tonsillitis?

Augmentin Dosing for Bacterial Tonsillitis in a 3-Year-Old, 22kg Child

For a 3-year-old child weighing 22kg with bacterial tonsillitis, prescribe Augmentin 457mg/5mL suspension at 12mL twice daily (approximately 990mg amoxicillin component per dose) for 10 days. 1

Weight-Based Calculation

• The recommended dose for Group A Streptococcal pharyngitis/tonsillitis is 50-75 mg/kg/day of the amoxicillin component divided into 2 doses 1
• For this 22kg child: 22kg × 50mg/kg = 1,100mg daily (550mg per dose twice daily) 1
• Using the 457mg/5mL suspension (which contains 400mg amoxicillin per 5mL): approximately 12mL twice daily provides the target dose 2, 3

Rationale for Augmentin vs Plain Amoxicillin

Plain amoxicillin at 50-75 mg/kg/day is actually the preferred first-line treatment for uncomplicated bacterial tonsillitis caused by Group A Streptococcus. 1, 4 The addition of clavulanate (Augmentin) is not necessary for typical streptococcal tonsillitis unless:

• The child has failed initial amoxicillin therapy 5, 3
• There is concern for β-lactamase-producing organisms 3
• The child has received antibiotics within the past 4-6 weeks 5, 3

Treatment Duration and Monitoring

• Complete the full 10-day course to prevent acute rheumatic fever and ensure adequate eradication of Group A Streptococcus 1, 4
• Clinical improvement should be evident within 48-72 hours of starting treatment 1
• If no improvement occurs after 48-72 hours, clinical reassessment is necessary to confirm the diagnosis and consider alternative antibiotics 1
• The child becomes non-contagious after 24 hours of appropriate antibiotic therapy 2

Administration Instructions

• Administer at the start of meals to minimize gastrointestinal intolerance and enhance clavulanate absorption 6, 4
• Shake the suspension well before each use 4
• Refrigeration is preferable but not required; discard any unused portion after 14 days 4

Common Pitfall to Avoid

The most critical error would be underdosing. If the prescription was written as "457/5mL" without specifying the volume, ensure the pharmacist and family understand this refers to the suspension concentration, not the dose. The actual dose should be clearly written as "12mL twice daily" to avoid confusion. 3