Is 5ml twice daily of Augmentin (amoxicillin/clavulanate) sufficient for a 3-year-old, 22kg child with bacterial tonsillitis?

Is 5ml Twice Daily of Augmentin Sufficient for a 3-Year-Old, 22kg Child with Bacterial Tonsillitis?

No, 5ml twice daily is grossly inadequate and represents dangerous underdosing that will likely lead to treatment failure and promote antibiotic resistance.

Correct Dosing for This Patient

For a 22kg child with bacterial tonsillitis (Group A Streptococcal pharyngitis), the correct dose is 50-75 mg/kg/day of the amoxicillin component divided into 2 doses for 10 days. 1

Weight-Based Calculation:

• Minimum dose: 22 kg × 50 mg/kg = 1,100 mg/day (550 mg per dose, twice daily) 1
• Maximum dose: 22 kg × 75 mg/kg = 1,650 mg/day (825 mg per dose, twice daily) 1

Volume Required (depends on suspension concentration):

• If using 125mg/5mL suspension: approximately 22-33 mL per dose
• If using 250mg/5mL suspension: approximately 11-16.5 mL per dose
• If using 400mg/5mL suspension: approximately 7-10 mL per dose

The prescribed 5ml twice daily provides only 200-400mg total daily (depending on concentration), which is only 18-36% of the minimum required dose. 2, 1

Why This Underdosing is Dangerous

Clinical Consequences:

• Treatment failure is virtually guaranteed - subtherapeutic doses fail to achieve adequate serum and tissue concentrations to overcome even susceptible organisms 3
• Promotes antimicrobial resistance - inadequate dosing creates selective pressure for resistant strains 3
• Risk of complications - untreated or inadequately treated Group A Streptococcal infections can lead to acute rheumatic fever, post-streptococcal glomerulonephritis, and peritonsillar abscess 4
• Prolonged illness - the child will remain symptomatic and contagious 5

Treatment Algorithm for Bacterial Tonsillitis

First-Line Therapy:

Amoxicillin alone is preferred over Augmentin for uncomplicated Group A Streptococcal pharyngitis 1

• Dose: 50-75 mg/kg/day divided into 2 doses 1
• Duration: 10 days (mandatory to prevent acute rheumatic fever) 4
• Expected response: Clinical improvement within 48-72 hours 1

When to Use Augmentin Instead:

Augmentin (amoxicillin/clavulanate) is indicated only if: 2, 3

• Recent antibiotic use within past 30 days
• Treatment failure with amoxicillin alone
• Suspected β-lactamase producing organisms
• Concurrent purulent acute otitis media

If Augmentin is truly indicated, the dose should be 90 mg/kg/day of the amoxicillin component in 2 divided doses (approximately 990 mg per dose for this 22kg child). 2, 3

Critical Monitoring Parameters

Expected Clinical Response:

• Fever should resolve within 24-48 hours 6
• Overall clinical improvement within 48-72 hours 1
• Child becomes non-contagious after 24 hours of appropriate antibiotic therapy 2

When to Reassess:

If no improvement after 48-72 hours, reevaluate for: 1

• Incorrect diagnosis (viral pharyngitis, infectious mononucleosis)
• Non-compliance with medication
• Resistant organism
• Peritonsillar abscess or other complication

Common Pitfalls to Avoid

Dosing Errors:

• Always verify the suspension concentration (125/31,250/62, or 400/57 mg/5mL) before calculating volume 3
• Never use age-based dosing alone - always calculate weight-based dosing for antibiotics 2
• Do not round down significantly - rounding from 11mL to 5mL represents a 55% dose reduction 3

Duration Errors:

• Never prescribe less than 10 days for Group A Streptococcal pharyngitis - shorter courses increase risk of acute rheumatic fever 4
• Complete the full course even if symptoms resolve - early discontinuation leads to relapse and recurrence 5, 7

Formulation Confusion:

• Standard-dose Augmentin (40-45 mg/kg/day) is inadequate for most indications 2, 3
• High-dose Augmentin (90 mg/kg/day) is the preferred formulation when Augmentin is indicated 2, 3

Immediate Action Required

This prescription must be corrected immediately. Contact the prescriber to clarify:

1. The intended suspension concentration
2. Whether amoxicillin alone or Augmentin is truly indicated
3. The correct volume based on 50-75 mg/kg/day dosing 1

Do not dispense this prescription as written - it represents a medication error that will harm the patient. 3