What is the appropriate Augmentin (amoxicillin‑clavulanate) dose for a 6‑year‑old child weighing 20 kg with normal renal function and no penicillin allergy?

Augmentin Dosing for a 20 kg, 6-Year-Old Child

For a 6-year-old child weighing 20 kg with normal renal function, prescribe Augmentin (amoxicillin-clavulanate) at 900 mg of the amoxicillin component twice daily (45 mg/kg/dose), which equals approximately 11 mL of the 400 mg/5 mL suspension administered every 12 hours.

Dosing Algorithm Based on Clinical Indication

The appropriate Augmentin dose depends on the specific infection and presence of risk factors for resistant organisms:

Standard-Dose Regimen (45 mg/kg/day)

• For uncomplicated respiratory infections in children ≥2 years without recent antibiotic exposure, daycare attendance, or severe illness, use 45 mg/kg/day divided into two doses (900 mg/day total = 450 mg twice daily). 1, 2
• This translates to 11 mL of 400 mg/5 mL suspension twice daily or 9 mL of 250 mg/5 mL suspension twice daily. 2, 3

High-Dose Regimen (90 mg/kg/day)

• Use 90 mg/kg/day divided into two doses (1,800 mg/day total = 900 mg twice daily) when any of these risk factors are present: 1, 2

  • Age < 2 years
  • Daycare attendance
  • Antibiotic use within the past 30 days
  • Moderate-to-severe illness
  • Geographic area with > 10% penicillin-resistant S. pneumoniae
  • Incomplete H. influenzae type b vaccination
  • Concurrent purulent otitis media

• For high-dose therapy, prescribe 22 mL of 400 mg/5 mL suspension twice daily or 18 mL of 250 mg/5 mL suspension twice daily. 1, 2

Indication-Specific Dosing

Community-Acquired Pneumonia

• Children < 5 years: 90 mg/kg/day in two doses for 10 days (900 mg twice daily for this 20 kg child). 1, 2
• Children ≥ 5 years: 90 mg/kg/day in two doses for 7–10 days. 1, 4
• The high-dose regimen achieves tissue concentrations that overcome penicillin-resistant S. pneumoniae (MIC up to 2–4 mg/L) and covers β-lactamase-producing H. influenzae and M. catarrhalis. 1, 2, 5

Acute Otitis Media

• Standard dose (45 mg/kg/day): For children ≥2 years without risk factors, give 450 mg twice daily for 10 days. 1, 2
• High dose (90 mg/kg/day): For children <2 years, recent antibiotic use, or severe presentation, give 900 mg twice daily for 10 days. 1, 2

Acute Bacterial Sinusitis

• Standard dose: 45 mg/kg/day for children ≥2 years without risk factors. 1
• High dose: 80–90 mg/kg/day for children <2 years, daycare attendees, or recent antibiotic exposure. 1

Practical Administration

Formulation Selection

• The 400 mg/5 mL (ES-600) suspension provides the optimal 14:1 amoxicillin-to-clavulanate ratio (90 mg/6.4 mg per kg/day) and causes less diarrhea than other formulations. 2, 6
• The FDA-approved dose for children ≥3 months is 45 mg/kg/day every 12 hours for standard infections or 90 mg/kg/day every 12 hours for severe infections. 3

Timing and Duration

• Administer at the start of meals to enhance clavulanate absorption and minimize gastrointestinal side effects. 3
• Standard treatment duration is 10 days for most respiratory infections, including otitis media and pneumonia. 1, 2
• Continue therapy for at least 48–72 hours after complete symptom resolution. 1

Clinical Monitoring

Expected Response

• Clinical improvement (reduced fever, improved respiratory symptoms) should occur within 48–72 hours of initiating therapy. 1, 2
• If no improvement or worsening after 48–72 hours: 1
  • Consider atypical pathogens (Mycoplasma, Chlamydophila) and add a macrolide
  • Reassess diagnosis with imaging if indicated
  • Evaluate for complications or treatment failure

When to Escalate or Switch

• Switch to alternative therapy if clinical failure occurs after 48–72 hours on appropriate high-dose Augmentin. 1
• For β-lactam allergy (non-anaphylactic), use cephalosporins (cefdinir, cefuroxime). 1
• For type I (IgE-mediated) allergy, use clindamycin or azithromycin, acknowledging inferior efficacy. 1

Critical Dosing Considerations

Maximum Doses

• Maximum single dose: 2,000 mg of amoxicillin component per administration. 2, 3
• Maximum daily dose: 4,000 mg of amoxicillin component per day. 1, 2

Common Pitfalls to Avoid

• Do not use the 250 mg/125 mg tablet formulation in children <40 kg, as the amoxicillin-to-clavulanate ratio differs from pediatric suspensions. 3
• Verify suspension concentration (125/31,250/62, or 400/57 mg per 5 mL) before calculating volume to prevent dosing errors. 2
• Do not underdose: Subtherapeutic concentrations promote resistance and lead to treatment failure, especially with resistant organisms. 2, 7
• Do not prescribe for viral infections: Most upper respiratory infections are viral and do not benefit from antibiotics. 2

Renal Impairment

• For this 6-year-old with normal renal function, no dose adjustment is needed. 3
• If glomerular filtration rate <30 mL/min, reduce frequency or avoid the 875/125 mg formulation entirely. 3

Evidence Strength

The high-dose Augmentin regimen (90 mg/kg/day) for pediatric respiratory infections is endorsed by the Infectious Diseases Society of America (IDSA) and the Pediatric Infectious Diseases Society (PIDS), reflecting strong guideline-based practice. 1, 2 This dosing achieves middle-ear and lung tissue concentrations sufficient to overcome penicillin-resistant S. pneumoniae with MICs up to 4 mg/L, as demonstrated in both pharmacokinetic studies and clinical trials. 2, 5