What is the appropriate Augmentin (amoxicillin/clavulanate) dose for a 79‑lb (≈36 kg) patient?

Augmentin Dosing for a 79-Pound Patient

For a 79-pound (36 kg) child, the standard Augmentin dose is 45 mg/kg/day divided twice daily (approximately 810 mg amoxicillin per day, or 405 mg per dose twice daily), while high-dose therapy is 90 mg/kg/day divided twice daily (approximately 1,620 mg amoxicillin per day, or 810 mg per dose twice daily). 1

Dosing Framework by Clinical Indication

For Acute Otitis Media or Sinusitis

Standard-dose regimen:

• Use 45 mg/kg/day of amoxicillin component divided twice daily for children ≥2 years without recent antibiotic exposure or daycare attendance 2
• For this 36 kg patient: approximately 405 mg amoxicillin per dose twice daily

High-dose regimen (preferred in most cases):

• Use 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate divided twice daily 2, 1
• For this 36 kg patient: approximately 810 mg amoxicillin per dose twice daily
• This high-dose formulation is specifically indicated for:
  • Children <2 years of age 2
  • Recent antibiotic use within past 30 days 2
  • Daycare attendance 2
  • Moderate to severe illness 2
  • Geographic areas with >10% penicillin-resistant S. pneumoniae 2

For Group A Streptococcal Carrier State

• Use 40 mg amoxicillin/kg/day divided three times daily (maximum 2,000 mg amoxicillin per day) 2
• For this 36 kg patient: approximately 480 mg amoxicillin per dose three times daily
• Duration: 10 days 2

For Acute Bacterial Rhinosinusitis

Mild disease without recent antibiotic use:

• Standard formulation: 1.75-4 g/day amoxicillin component for adults 2
• Pediatric: 90 mg/kg/day amoxicillin with 6.4 mg/kg/day clavulanate divided twice daily 2

Moderate disease or recent antibiotic exposure:

• High-dose amoxicillin/clavulanate: 4 g/250 mg per day for adults 2
• Pediatric: 90 mg/kg/day amoxicillin with 6.4 mg/kg/day clavulanate 2

Practical Prescribing Considerations

Available Formulations

The FDA-approved high-dose pediatric formulation (Augmentin ES-600) provides:

• 600 mg amoxicillin/42.9 mg clavulanate per 5 mL 1
• This formulation achieves the 14:1 ratio of amoxicillin to clavulanate needed for high-dose therapy 2, 1
• For a 36 kg patient on high-dose therapy: approximately 6.75 mL twice daily 1

Critical Dosing Pitfalls

Do not substitute standard formulations for high-dose therapy:

• The 200 mg/28.5 mg per 5 mL and 400 mg/57 mg per 5 mL suspensions contain different clavulanate ratios and are NOT interchangeable with ES-600 1
• Standard formulations provide inadequate amoxicillin dosing for resistant pathogens 2, 1

Clavulanate dose limitations:

• Adult formulations restrict clavulanate to 125 mg per dose due to gastrointestinal tolerability 3
• Pediatric high-dose formulation maintains 6.4 mg/kg/day clavulanate to minimize adverse effects while preserving β-lactamase inhibition 1

Administration Guidelines

• Administer at the start of meals to minimize gastrointestinal intolerance and enhance clavulanate absorption 1
• Shake suspension well before each use 1
• Refrigerate reconstituted suspension; stable for 10 days 1

Duration of Therapy

• Acute otitis media: 10 days 2, 1
• Acute bacterial sinusitis: 10 days 2
• Group A streptococcal carrier: 10 days 2

Monitoring for Treatment Failure

Reassess if no improvement after 48-72 hours:

• Consider switch to ceftriaxone 50 mg/kg IM/IV daily for 3 days 2
• Alternative: combination therapy with clindamycin plus third-generation cephalosporin 2
• May require tympanocentesis for culture if multiple treatment failures 2