Augmentin 457mg/5mL Dosing for a 3-Year-Old, 22kg Child with Bacterial Tonsillitis
For a 22kg child with bacterial tonsillitis, administer 10mL of Augmentin 457mg/5mL (which provides 90mg/kg/day of amoxicillin) twice daily for 10 days. 1
Dosing Calculation and Rationale
The high-dose regimen of 90mg/kg/day divided into 2 doses is the appropriate choice for this clinical scenario. 1 This translates to:
- 22kg × 90mg/kg/day = 1,980mg amoxicillin per day
- Divided into 2 doses = 990mg per dose
- Using the 457mg/5mL suspension: approximately 10mL twice daily 1
The 457mg/5mL formulation is specifically designed to deliver the high-dose regimen (90mg/kg/day with 6.4mg/kg/day clavulanate) in a 14:1 ratio, which minimizes gastrointestinal side effects while maintaining efficacy against resistant organisms. 1
Why High-Dose Therapy for Tonsillitis
High-dose amoxicillin-clavulanate is indicated for this patient based on several risk factors: 1
- Age <2 years (though this child is 3, the threshold varies by guideline)
- Potential for β-lactamase producing organisms
- Need for adequate coverage against penicillin-resistant Streptococcus pneumoniae 1
For Group A Streptococcal tonsillitis specifically, amoxicillin alone at 50-75mg/kg/day would typically suffice. 2 However, if bacterial tonsillitis of uncertain etiology or mixed infection is suspected, the amoxicillin-clavulanate combination provides broader coverage against β-lactamase producing Haemophilus influenzae and Moraxella catarrhalis. 3
Administration Guidelines
Administer at the start of meals to enhance clavulanate absorption and minimize gastrointestinal intolerance. 4 The medication may be taken without regard to meals, but starting with food significantly reduces the risk of diarrhea. 4
Treatment Duration and Monitoring
Complete the full 10-day course of therapy. 1 For bacterial tonsillitis, this duration ensures adequate eradication of pathogens and prevents complications. 1
Clinical improvement should be evident within 48-72 hours: 1
- Fever should resolve within 24-48 hours
- Throat pain should begin improving by day 2-3
- If no improvement or worsening occurs after 72 hours, reassess the diagnosis and consider alternative pathogens or complications 1
Common Pitfalls to Avoid
Do not use lower-dose formulations (125/31 or 250/62) for this weight and indication. 1 The 457mg/5mL suspension is specifically formulated to deliver high-dose therapy with the optimal 14:1 ratio that reduces diarrhea compared to other amoxicillin-clavulanate preparations. 1
Verify the suspension concentration before dispensing. 1 Dosing errors commonly occur when providers confuse different suspension strengths. The 457mg/5mL formulation is distinct from the 125/31mg/5mL or 250/62mg/5mL suspensions. 1
Do not underdose. 1 Subtherapeutic doses fail to achieve adequate tissue concentrations, promote antimicrobial resistance, and lead to treatment failure with resistant organisms. 1
Expected Adverse Effects
The most common adverse effect is diarrhea, occurring in approximately 7-10% of patients. 5 The twice-daily high-dose formulation (14:1 ratio) causes less diarrhea than three-times-daily standard formulations while maintaining equivalent efficacy. 1, 5 Other potential adverse effects include nausea, vomiting, and rash. 1
Maximum Dose Considerations
Although this child's calculated dose (1,980mg/day) is well below the maximum daily dose of 4,000mg/day, always verify that individual doses do not exceed 2,000mg per dose regardless of weight. 1, 4