What is the appropriate dosing of amoxicillin-clavulanate (amox-clav) for pediatric patients?

Pediatric Dosing of Amoxicillin-Clavulanate

For most pediatric infections in children ≥12 weeks, use high-dose amoxicillin-clavulanate at 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate divided into 2 doses (maximum 4000 mg/day), given as a 14:1 ratio formulation. 1, 2

Age-Based Dosing Algorithm

Neonates and Infants <12 Weeks

• 30 mg/kg/day divided every 12 hours based on the amoxicillin component 3
• Use the 125 mg/5 mL oral suspension (experience with 200 mg/5 mL formulation is limited in this age group) 3

Children ≥12 Weeks to <40 kg

Standard-Dose Regimen (Less Severe Infections):

• 25 mg/kg/day every 12 hours OR 20 mg/kg/day every 8 hours 1
• Use for uncomplicated infections without risk factors 1

High-Dose Regimen (More Severe Infections or Risk Factors Present):

• 90 mg/kg/day every 12 hours (preferred) OR 80 mg/kg/day every 8 hours 1, 2
• Provides 6.4 mg/kg/day of clavulanate in the twice-daily regimen 2
• Maximum daily dose: 4000 mg amoxicillin 2

Children ≥40 kg

• Dose according to adult recommendations 3
• Standard: 500 mg/125 mg every 8 hours OR 875 mg/125 mg every 12 hours 3
• High-dose for severe infections: 2000 mg/125 mg every 12 hours 1

Indications for High-Dose Therapy

Always use high-dose (90 mg/kg/day) when ANY of these risk factors are present: 2

• Age <2 years 2
• Daycare attendance 2, 4
• Recent antibiotic use within previous 30 days 2, 4
• Incomplete Haemophilus influenzae type b vaccination (<3 injections) 2
• Geographic area with high prevalence (>10%) of penicillin-resistant S. pneumoniae 2, 4
• Moderate to severe illness 2
• Concurrent purulent conjunctivitis (otitis-conjunctivitis syndrome) 4
• Failed previous amoxicillin therapy 1

Infection-Specific Dosing

Acute Otitis Media

• High-dose: 90 mg/kg/day divided BID for 10 days 2, 3
• Use high-dose if amoxicillin given in previous 30 days or concurrent conjunctivitis 1
• Predicted clinical efficacy: 90-92% against penicillin-resistant S. pneumoniae 2

Acute Bacterial Rhinosinusitis

• Children: 90 mg/kg/day divided BID for 10-14 days 1, 2
• High-dose is strongly recommended as first-line therapy 2

Community-Acquired Pneumonia

• Children <5 years: 90 mg/kg/day divided BID for 10 days 2
• Children ≥5 years: 90 mg/kg/day divided BID (maximum 4000 mg/day) for 10 days 2
• Consider starting with amoxicillin alone (80-100 mg/kg/day) in children <3 years without risk factors, adding clavulanate if necessary 2

β-lactamase Producing Organisms

• 45 mg/kg/day in 3 doses OR 90 mg/kg/day in 2 doses 2
• Maximum 2 g per dose 2

Practical Age-Based Suspension Dosing

For standard-dose infections (NOT high-dose): 1

• Birth to 1 year: 2.5 mL of 125/31 suspension three times daily 1
• 1-6 years: 5 mL of 125/31 suspension three times daily 1
• 7-12 years: 5 mL of 250/62 suspension three times daily 1
• 12-18 years: 1 tablet (250/125) three times daily 1

Note: The every-12-hour regimen is preferred over every-8-hour dosing as it causes significantly less diarrhea 3

Duration of Therapy

• Acute otitis media: 10 days 2, 3
• Acute bacterial rhinosinusitis: 10-14 days for children (longer than adults) 1, 2
• Community-acquired pneumonia: 10 days 2
• Uncomplicated UTI: 3-7 days 1
• Continue for 7 days after symptom resolution to ensure complete eradication 2

Critical Dosing Considerations

The 14:1 ratio formulation (90/6.4 mg/kg/day) causes less diarrhea than other amoxicillin-clavulanate preparations while maintaining efficacy. 2, 5 This formulation doubles the amoxicillin dose while keeping clavulanate constant, reducing gastrointestinal side effects 6

Do NOT substitute formulations: 3

• Two 250 mg/125 mg tablets ≠ one 500 mg/125 mg tablet (different clavulanate amounts) 3
• 250 mg/125 mg tablet ≠ 250 mg/62.5 mg chewable tablet 3

Verify suspension concentration before dispensing (125/31 vs 250/62) to avoid dosing errors 2

Monitoring and Response

• Evaluate clinical response within 48-72 hours of initiating therapy 1, 2
• If no improvement or worsening after 72 hours: reassess diagnosis, consider atypical pathogens, evaluate for complications, or switch antibiotics 2, 4
• Clinical improvement should be evident within 48-72 hours for most infections 2

Renal Impairment Adjustments

• GFR 10-30 mL/min: 500 mg/125 mg or 250 mg/125 mg every 12 hours 3
• GFR <10 mL/min: 500 mg/125 mg or 250 mg/125 mg every 24 hours 3
• Hemodialysis: 500 mg/125 mg or 250 mg/125 mg every 24 hours, with additional dose during and at end of dialysis 3
• Dose reduction essential to avoid accumulation in renal insufficiency 4

Common Pitfalls to Avoid

Underdosing in areas with high penicillin-resistant S. pneumoniae prevalence leads to treatment failure and promotes antimicrobial resistance. 1 Standard doses achieve inadequate serum and tissue concentrations against resistant organisms 2

Using standard-dose when high-dose is indicated results in 20-25% treatment failure rates when risk factors for resistant organisms are present 4

Most upper respiratory tract infections are viral and do not require antibiotics at all. 2 Ensure diagnostic criteria for bacterial infection are met before prescribing 2