What is the recommended dose of Co-Amoxiclav (amoxicillin/clavulanic acid) for a child weighing 16.9 kg using a 457mg/5ml suspension?

Co-Amoxiclav Dosing for a 16.9 kg Child

For a 16.9 kg child, the recommended dose is 90 mg/kg/day of the amoxicillin component divided into 2 doses, which equals 760.5 mg twice daily, administered as 8.3 mL of the 457 mg/5 mL suspension twice daily. 1

Dosing Calculation

Standard High-Dose Regimen

• The preferred dosing for most pediatric infections is 90 mg/kg/day of the amoxicillin component divided into 2 doses, particularly for respiratory tract infections in areas with high pneumococcal resistance or when β-lactamase-producing organisms are suspected 1, 2

• For a 16.9 kg child:

  • Total daily dose: 16.9 kg × 90 mg/kg = 1,521 mg/day 1
  • Per-dose amount: 1,521 mg ÷ 2 = 760.5 mg per dose 1

Volume Calculation with 457 mg/5 mL Suspension

• The 457 mg/5 mL suspension contains 91.4 mg of amoxicillin per mL 3

• Volume per dose: 760.5 mg ÷ 91.4 mg/mL = 8.3 mL twice daily 1, 3

• Administer 8.3 mL of the suspension every 12 hours 1

Alternative Standard-Dose Regimen

• For mild to moderate infections where resistant pathogens are less likely, a standard dose of 45 mg/kg/day divided into 2 doses may be used 1, 2

• For a 16.9 kg child using standard dosing:

  • Total daily dose: 16.9 kg × 45 mg/kg = 760.5 mg/day 1
  • Per-dose amount: 760.5 mg ÷ 2 = 380.25 mg per dose 1
  • Volume per dose: 380.25 mg ÷ 91.4 mg/mL = 4.2 mL twice daily 1

Clinical Context for Dose Selection

When to Use High-Dose (90 mg/kg/day)

• Respiratory tract infections including pneumonia 1, 4
• Recent antibiotic exposure within the past 3 months 1
• Areas with high pneumococcal resistance 1, 2
• Suspected β-lactamase-producing Haemophilus influenzae 1, 2
• Inadequate H. influenzae type b vaccination 1
• Concurrent purulent acute otitis media 1

When Standard-Dose (45 mg/kg/day) May Be Appropriate

• Mild to moderate infections without risk factors for resistance 1, 2
• Group A Streptococcal infections (though 50-75 mg/kg/day is preferred for this indication) 1

Administration Guidelines

• Administer at the start of meals to minimize gastrointestinal intolerance 3
• Shake suspension well before each use 3
• Store reconstituted suspension in refrigerator (preferred but not required) 3
• Discard any unused suspension after 14 days 3

Treatment Duration

• Continue treatment for 7-10 days for most respiratory infections 1
• For pneumonia specifically, treat for 10 days 1, 4
• Treat for a minimum of 48-72 hours beyond symptom resolution 1, 4

Maximum Dose Considerations

• The absolute maximum daily dose is 4,000 mg of amoxicillin component per day, regardless of weight 2
• At 90 mg/kg/day, this 16.9 kg child receives 1,521 mg/day, which is well below the maximum 2

Common Pitfalls to Avoid

• Do not use the 875 mg tablet formulation in children under 40 kg 3
• Do not confuse the amoxicillin component dose with the total Co-Amoxiclav dose (the suspension contains both amoxicillin and clavulanic acid) 2, 3
• Avoid underdosing in the setting of resistant pathogens by using 90 mg/kg/day rather than 45 mg/kg/day when indicated 1, 2
• Do not extend dosing intervals beyond 12 hours for the twice-daily regimen, as this compromises the time above MIC 1
• Ensure clinical improvement within 48-72 hours; if no improvement occurs, reevaluation is necessary 1