What is the recommended dose of co-amoxiclav (amoxicillin/clavulanic acid) for a 30kg child?

Co-Amoxiclav Dosing for a 30kg Child

For a 30kg child, administer co-amoxiclav at 45 mg/kg/day of the amoxicillin component divided into two daily doses (approximately 675 mg amoxicillin twice daily), or 90 mg/kg/day divided into two doses (1350 mg amoxicillin twice daily) for resistant organisms or severe infections.

Standard Dosing Recommendations

The recommended dose depends on the indication and severity of infection:

For β-lactamase-producing Haemophilus influenzae or mild-to-moderate infections:

• Administer 45 mg/kg/day of the amoxicillin component in 2 divided doses (approximately 675 mg amoxicillin per dose, twice daily) 1
• This provides adequate coverage for β-lactamase-producing organisms while minimizing gastrointestinal side effects 1

For resistant Streptococcus pneumoniae or severe infections:

• Administer 90 mg/kg/day of the amoxicillin component in 2 divided doses (1350 mg amoxicillin per dose, twice daily) 1, 2
• This high-dose regimen is essential for overcoming pneumococcal resistance and is the standard for community-acquired pneumonia 2

Practical Calculation for a 30kg Child

Standard-dose regimen (45 mg/kg/day):

• Total daily dose: 1350 mg amoxicillin (45 mg/kg × 30 kg) 1
• Per-dose amount: 675 mg amoxicillin twice daily 1
• Using the 4:1 ratio formulation, this equals approximately 844 mg co-amoxiclav per dose (675 mg amoxicillin + 169 mg clavulanate) 1

High-dose regimen (90 mg/kg/day):

• Total daily dose: 2700 mg amoxicillin (90 mg/kg × 30 kg) 2
• Per-dose amount: 1350 mg amoxicillin twice daily 2
• Using the 14:1 ratio formulation (Augmentin ES-600), this equals approximately 1446 mg co-amoxiclav per dose 3

Indication-Specific Dosing

For community-acquired pneumonia:

• Use the high-dose regimen (90 mg/kg/day in 2 doses) as first-line treatment 2
• This provides optimal coverage for Streptococcus pneumoniae, including resistant strains 2

For acute otitis media or sinusitis:

• Use 90 mg/kg/day in 2 doses for recurrent or persistent infections after amoxicillin failure 3
• Standard-dose (45 mg/kg/day) may be considered for initial episodes without recent antibiotic exposure 3

For skin and soft tissue infections:

• Use 45 mg/kg/day in 2 doses for suspected Staphylococcus aureus (MSSA) with β-lactamase production 2

Critical Dosing Considerations

Twice-daily vs. three-times-daily dosing:

• Twice-daily dosing is preferred for improved compliance and reduced gastrointestinal side effects 4, 3
• Pharmacokinetic studies demonstrate adequate time above MIC with twice-daily administration 4

Common dosing errors to avoid:

• Never underdose at 40-45 mg/kg/day when treating pneumonia—this is inadequate for resistant organisms 2, 5
• Do not use three-times-daily dosing when twice-daily is appropriate, as this increases diarrhea rates 3
• Ensure proper ratio formulation: use 14:1 (amoxicillin:clavulanate) for high-dose regimens to minimize clavulanate-related diarrhea 3

Administration Guidelines

Timing with meals:

• Administer at the start of meals to enhance clavulanate absorption and reduce gastrointestinal side effects 6
• Food minimally affects amoxicillin absorption but significantly improves clavulanate bioavailability 6

Duration of therapy:

• 5-7 days for most respiratory infections including pneumonia and otitis media 2
• Extend to 10-14 days for complicated infections or slow clinical response 2

Monitoring and Adjustment

Expected clinical response:

• Improvement should occur within 48-72 hours of initiating therapy 2
• If no improvement occurs, consider treatment failure, resistant organisms, or alternative diagnoses 2

Side effects:

• Diarrhea is the most common adverse effect (22-44% incidence), typically mild and self-limiting 7
• Twice-daily dosing reduces diarrhea compared to three-times-daily administration 3
• The high-dose 14:1 ratio formulation has similar tolerability to standard formulations 3