Amoxicillin-Clavulanate (Amoxiclav) Dosing in Children
For most pediatric infections, use high-dose amoxicillin-clavulanate at 90 mg/kg/day of the amoxicillin component with 6.4 mg/kg/day of clavulanate, divided into 2 doses daily, with a maximum single dose of 2000 mg. 1
Standard Dosing Regimens
High-Dose Regimen (Preferred for Most Infections)
- 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in 2 divided doses is the recommended high-dose regimen for children 2, 1
- This provides a 14:1 ratio of amoxicillin to clavulanate, which causes less diarrhea than other formulations while maintaining efficacy 1
- Maximum single dose is 2 grams regardless of weight 1
Standard-Dose Regimen (Limited Use)
- 45 mg/kg/day of amoxicillin divided into 3 doses or 90 mg/kg/day divided into 2 doses for β-lactamase producing organisms 1
- This lower dose is generally inadequate for resistant organisms and should be avoided in most clinical scenarios 1
Age-Based Oral Suspension Dosing
For standard-dose regimens (when specifically indicated):
- Less than 1 year (1-12 months): 2.5 ml three times daily of 125/31 suspension 1
- 1-6 years: 5 ml three times daily of 125/31 suspension 1
- 7-12 years: 5 ml three times daily of 250/62 suspension 1
- 12-18 years: 1 tablet (250/125) three times daily 1
Specific Clinical Indications
Community-Acquired Pneumonia
- Outpatient children <5 years: 90 mg/kg/day of amoxicillin component in 2 doses 2, 1
- Outpatient children ≥5 years: 90 mg/kg/day in 2 doses (maximum 4000 mg/day, e.g., one 2000-mg tablet twice daily) 2
- Treatment duration is 10 days for bacterial pneumonia 1
Acute Otitis Media and Sinusitis
- High-dose therapy (90/6.4 mg/kg/day in 2 doses) is indicated for areas with >10% prevalence of penicillin-resistant Streptococcus pneumoniae 1
- Treatment courses of 10 days are recommended for most pediatric infections 1
Respiratory Tract Infections with β-lactamase Producing Organisms
- For β-lactamase producing H. influenzae: 90 mg/kg/day in 2 doses 1
High-Dose Therapy Risk Factors
Use high-dose amoxicillin-clavulanate (90/6.4 mg/kg/day) when ANY of these risk factors are present:
- Age <2 years 1
- Daycare attendance 1, 3
- Recent antibiotic use (within 30 days) 1, 3
- Moderate to severe illness 1
- Incomplete vaccination against Haemophilus influenzae type b (less than 3 injections) 1
- Concurrent purulent otitis media with pneumonia 1
- Treatment failure with standard amoxicillin 1
- Concurrent conjunctivitis (provides coverage for Moraxella catarrhalis) 3
Intravenous Dosing
- All pediatric ages: 30 mg/kg three times daily IV 1
- For an 18 kg child, this would be 540 mg IV three times daily 1
Critical Clinical Considerations
Pharmacokinetic Rationale
- High-dose amoxicillin (80-90 mg/kg/day) exceeds the minimum inhibitory concentration for intermediately resistant S. pneumoniae and many highly resistant serotypes 1
- Serum levels of amoxicillin increase linearly with dose, and the difference in adverse effects between lower and higher doses is generally negligible 1
- The 14:1 ratio formulation causes significantly less diarrhea than other amoxicillin-clavulanate preparations 1
Common Pitfalls to Avoid
Always verify the suspension concentration (125/31 vs 250/62) before calculating volume to avoid dosing errors 1
- Using standard doses when high-dose therapy is indicated leads to inevitable treatment failure with resistant organisms 1
- Subtherapeutic doses fail to achieve adequate serum and tissue concentrations to overcome even susceptible organisms and promote antimicrobial resistance 1
- Most upper respiratory tract infections are viral and do not require antibiotics at all—ensure bacterial infection criteria are met before prescribing 1
Adverse Effects
- Common adverse effects include diarrhea, nausea, vomiting, and rash 1
- The high-dose 14:1 formulation is less likely to cause diarrhea than other preparations 1, 3