Amoxicillin-Clavulanate (Amoxyclav) Pediatric Dosing
For most pediatric respiratory tract infections, the recommended dose is 90 mg/kg/day of the amoxicillin component divided into 2 doses (maximum 4000 mg/day), which provides optimal coverage against resistant organisms including penicillin-resistant Streptococcus pneumoniae and β-lactamase producing Haemophilus influenzae. 1, 2
Standard Dosing Regimens by Age and Weight
Infants and Children Under 40 kg
High-Dose Regimen (Preferred for Most Infections):
- 90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day of clavulanate, divided into 2 doses 1, 2
- This provides a 14:1 ratio of amoxicillin to clavulanate, which minimizes diarrhea while maintaining efficacy 2
- Maximum single dose: 2000 mg regardless of weight 2
Standard-Dose Regimen (Mild Infections Only):
- 45 mg/kg/day in 3 divided doses OR 90 mg/kg/day in 2 divided doses for β-lactamase producing organisms 2
- This lower dose should only be used for mild infections in areas with low resistance 2
Age-Based Oral Suspension Dosing (Alternative Approach)
For standard-dose therapy using 125/31 suspension 2:
- Less than 1 year (1-12 months): 2.5 mL three times daily
- 1-6 years: 5 mL three times daily
- 7-12 years: 5 mL three times daily of 250/62 suspension
- 12-18 years: 1 tablet (250/125) three times daily
Critical Note: These age-based doses provide substantially lower amoxicillin amounts than the recommended high-dose regimen and should generally be avoided for respiratory infections where resistant organisms are suspected 2.
Specific Clinical Indications
Community-Acquired Pneumonia
- Children <5 years: 90 mg/kg/day of amoxicillin component in 2 doses 1, 2
- Children ≥5 years: 90 mg/kg/day in 2 doses (maximum 4000 mg/day) 2
- Duration: 10 days 1, 2
β-Lactamase Producing H. influenzae
- 45 mg/kg/day in 3 doses OR 90 mg/kg/day in 2 doses of the amoxicillin component 1, 2
- The twice-daily high-dose regimen is preferred for better adherence 1
Acute Otitis Media with Risk Factors
High-dose therapy (90/6.4 mg/kg/day in 2 doses) is indicated for children with 2:
- Age <2 years
- Daycare attendance
- Recent antibiotic use (within 3 months)
- Moderate to severe illness
- Incomplete H. influenzae type b vaccination (<3 injections)
Critical Dosing Considerations
When High-Dose Therapy is Essential
The American Academy of Pediatrics emphasizes that using standard doses when high-dose therapy is indicated leads to inevitable treatment failure with resistant organisms. 2 High-dose amoxicillin (80-90 mg/kg/day) exceeds the minimum inhibitory concentration for intermediately resistant S. pneumoniae and many highly resistant serotypes 2.
Renal Impairment
For children >40 kg with severe renal impairment 3:
- GFR 10-30 mL/min: 500 mg or 250 mg every 12 hours
- GFR <10 mL/min: 500 mg or 250 mg every 24 hours
- Hemodialysis: Additional dose during and at end of dialysis
Infants <3 Months
- Maximum dose: 30 mg/kg/day divided every 12 hours due to immature renal function 3
- Treatment duration: minimum 48-72 hours beyond symptom resolution 3
Administration and Monitoring
Key Administration Points
- Take at the start of meals to minimize gastrointestinal intolerance 3
- Shake oral suspension well before each use 3
- Reconstituted suspension stable for 14 days; refrigeration preferred but not required 3
Expected Clinical Response
- Clinical improvement should occur within 48-72 hours 1, 2
- If no improvement or worsening after 72 hours, reevaluate and consider switching antibiotics or further investigation 2
- Continue therapy for minimum 48-72 hours beyond symptom resolution 3
Common Pitfalls to Avoid
Underdosing Errors
Subtherapeutic doses fail to achieve adequate serum and tissue concentrations to overcome even susceptible organisms and promote antimicrobial resistance. 2 An 80 mg total daily dose for a 5-year-old child (as mentioned in some contexts) is grossly inadequate—the correct dose for an 18 kg child would be approximately 375 mg daily (21 mg/kg/day) at minimum, or preferably 1620 mg daily (90 mg/kg/day) for high-dose therapy 2.
Formulation Confusion
Always verify the suspension concentration (125/31 vs 250/62) before calculating volume to avoid dosing errors 2. The high-dose 14:1 ratio formulation is specifically designed to provide 90 mg/kg amoxicillin with only 6.4 mg/kg clavulanate, reducing diarrhea compared to other formulations 2.
Inappropriate Antibiotic Use
Most upper respiratory tract infections are viral and do not benefit from antibiotics 2. Before prescribing, ensure the child meets criteria for bacterial infection such as acute bacterial rhinosinusitis (persistent symptoms >10 days without improvement, severe symptoms, or "double sickening") 2.
Adverse Effects
- Most common: diarrhea, nausea, vomiting (generally mild) 1, 4
- Diarrhea is less frequent with twice-daily versus three-times-daily dosing 2, 4
- The high-dose 14:1 formulation causes less diarrhea than other amoxicillin-clavulanate preparations while maintaining efficacy 2
- Rash and hypersensitivity reactions may occur 1