What is the therapeutic dose of co-amoxiclav (amoxicillin/clavulanic acid) 457mg/5ml, given twice daily (BID), for a 5-year-old child with an upper respiratory tract infection (URTI)?

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Co-Amoxiclav Dosing for 5-Year-Old with URTI

For a 5-year-old child with an upper respiratory tract infection (URTI), co-amoxiclav 457mg/5ml should NOT be used as first-line therapy; plain amoxicillin is the preferred initial treatment unless there are specific indications for broader coverage. 1

First-Line Treatment Recommendation

  • Amoxicillin alone at 45 mg/kg/day divided into 2 doses is the recommended first-line therapy for children under 5 years with respiratory tract infections, as it effectively covers the most common pathogens (Streptococcus pneumoniae, non-β-lactamase producing Haemophilus influenzae) and is well-tolerated and cost-effective. 1

  • For more severe infections or areas with high pneumococcal resistance, increase to 90 mg/kg/day divided into 2 doses. 1, 2

When Co-Amoxiclav IS Indicated

Co-amoxiclav (amoxicillin/clavulanate) becomes appropriate in specific scenarios:

  • Inadequate H. influenzae type b vaccination status 2
  • Concurrent purulent acute otitis media 2
  • Suspected β-lactamase producing organisms (particularly H. influenzae or Moraxella catarrhalis) 1
  • Failed initial amoxicillin therapy after 48-72 hours 1, 2

Correct Dosing IF Co-Amoxiclav Is Used

If co-amoxiclav is clinically indicated, the dosing should be based on the amoxicillin component:

  • Standard dose: 45 mg/kg/day of amoxicillin component divided into 2 doses (every 12 hours) 1, 2
  • High dose: 90 mg/kg/day of amoxicillin component divided into 2 doses for severe infections or resistant organisms 1, 2

Practical Calculation for 457mg/5ml Suspension

The 457mg/5ml formulation contains approximately 400mg amoxicillin + 57mg clavulanate per 5ml (7:1 ratio). 3, 4

For a typical 5-year-old weighing approximately 18-20 kg:

  • Standard dose (45 mg/kg/day): 810-900 mg/day total = 5ml twice daily (approximately 400mg per dose)
  • High dose (90 mg/kg/day): 1620-1800 mg/day total = 10ml twice daily (approximately 800mg per dose)

Treatment Duration and Monitoring

  • Continue therapy for 7-10 days for most respiratory infections. 2, 5
  • Reassess at 48-72 hours if no clinical improvement is observed; further investigation or treatment modification may be necessary. 1, 2
  • Complete the full course even if symptoms improve before completion. 2

Critical Pitfalls to Avoid

  • Do not use co-amoxiclav as routine first-line therapy for simple URTIs in fully immunized children, as this promotes unnecessary resistance and increases side effects (particularly diarrhea). 1, 6
  • Ensure dosing is based on the amoxicillin component, not the total combination weight. 1, 2
  • Shake suspension well before each use and refrigerate after reconstitution (though not required); discard after 14 days. 5
  • Most URTIs are viral and may not require antibiotics at all; young children with mild lower respiratory symptoms need not be treated with antibiotics. 1

References

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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