What is the appropriate dose of co-amoxiclav (amoxicillin/clavulanate) for a 13kg patient?

Co-amoxiclav Dosing for a 13kg Child

For a 13kg child, the appropriate dose of co-amoxiclav (amoxicillin/clavulanate) 312.5mg/5ml suspension is 6.5ml every 8 hours for 7 days, providing approximately 45mg/kg/day of amoxicillin component.

Dosing Calculation

The dosing of co-amoxiclav depends on several factors including:

• Weight of the child
• Formulation concentration
• Severity of infection
• Risk of resistant organisms

Standard Dosing Approach

• For mild infections with no recent antibiotic exposure:

  • Standard dose: 45mg/kg/day of amoxicillin component divided into 3 doses (every 8 hours) 1
  • For a 13kg child: 13kg × 45mg/kg/day = 585mg/day
  • Divided into 3 doses = 195mg per dose
  • With 312.5mg/5ml suspension: 195mg ÷ (312.5mg/5ml) = 3.12ml per dose
  • Rounded to practical volume: 3ml per dose every 8 hours 1

• For moderate infections or with recent antibiotic exposure:

  • High dose: 90mg/kg/day of amoxicillin component divided into 2-3 doses 1
  • For a 13kg child: 13kg × 90mg/kg/day = 1170mg/day
  • Divided into 3 doses = 390mg per dose
  • With 312.5mg/5ml suspension: 390mg ÷ (312.5mg/5ml) = 6.24ml per dose
  • Rounded to practical volume: 6.5ml per dose every 8 hours 1

Clinical Considerations

Infection Severity and Resistance Risk

• Standard dose (45mg/kg/day) is appropriate for:

  • Mild infections
  • No recent antibiotic exposure
  • Low risk of resistant pathogens 1

• High dose (90mg/kg/day) is recommended for:

  • Moderate infections
  • Recent antibiotic use (within past 4-6 weeks)
  • Child care attendance (risk factor for resistant organisms)
  • Areas with high prevalence of resistant S. pneumoniae 1

Duration of Therapy

• 7 days is generally appropriate for most common infections 1
• For certain infections like pneumonia or more severe presentations, treatment may be extended to 10-14 days 1

Formulation Considerations

• The 312.5mg/5ml suspension contains 250mg amoxicillin and 62.5mg clavulanate per 5ml 1
• Shake well before each use to ensure uniform distribution of medication
• Store according to manufacturer's instructions (typically refrigerated after reconstitution) 2

Common Pitfalls to Avoid

• Underdosing: Insufficient dosing may lead to treatment failure and promote resistance 1
• Incorrect frequency: Co-amoxiclav at this concentration should be given every 8 hours rather than twice daily to maintain adequate drug levels 3, 4
• Not accounting for weight: Always calculate dose based on actual body weight, not age 1
• Not considering resistance patterns: In areas with high resistance, higher dosing may be necessary 1

Monitoring

• Assess clinical response within 48-72 hours
• Monitor for adverse effects, particularly diarrhea which is the most common side effect 5
• If no improvement after 72 hours, reevaluate diagnosis or consider alternative antibiotics 1