What is the recommended pediatric dose of amoxicillin‑clavulanic acid (amoxicillin component) for common infections such as acute otitis media, sinusitis, and uncomplicated pneumonia?

Pediatric Amoxicillin-Clavulanate Dosing for Common Infections

For most common pediatric infections including acute otitis media, sinusitis, and uncomplicated pneumonia, 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 (maximum 4000 mg/day amoxicillin). 1

Standard High-Dose Regimen

• The 90/6.4 mg/kg/day regimen provides a 14:1 ratio of amoxicillin to clavulanate, which achieves middle ear fluid concentrations adequate to overcome penicillin-resistant Streptococcus pneumoniae while minimizing gastrointestinal side effects compared to older formulations. 1, 2

• This high-dose formulation demonstrates 90-92% predicted clinical efficacy against drug-resistant S. pneumoniae and β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis. 1

• Maximum single dose is 2000 mg of amoxicillin regardless of weight. 1

When High-Dose Therapy Is Mandatory

High-dose amoxicillin-clavulanate (90/6.4 mg/kg/day) is strongly indicated for children with any of these risk factors: 1

• Age < 2 years
• Daycare attendance
• Recent antibiotic use within the previous 30 days
• Incomplete Haemophilus influenzae type b vaccination (< 3 injections)
• Geographic area with > 10% prevalence of penicillin-resistant S. pneumoniae
• Moderate to severe illness at presentation
• Concurrent purulent conjunctivitis or otitis media

Age-Based Volume Dosing (Alternative Approach)

For standard infections when weight-based calculation is impractical, age-based dosing may be used: 1

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

Critical caveat: These age-based volumes provide substantially lower total daily doses (approximately 21-25 mg/kg/day) than the recommended high-dose regimen and should only be used for uncomplicated infections in children without risk factors. 1

Specific Infection Dosing

Acute Otitis Media

• First-line: 90 mg/kg/day amoxicillin + 6.4 mg/kg/day clavulanate divided twice daily for 10 days. 1, 2
• Clinical trials demonstrate 96% eradication of S. pneumoniae (including 91% of penicillin-resistant strains with MICs 2-4 µg/mL) and 94% eradication of H. influenzae. 3
• Clinical improvement should occur within 48-72 hours; if not, switch to ceftriaxone 50 mg/kg IM/IV daily. 1, 2

Acute Bacterial Rhinosinusitis

• Children ≥ 3 months: 90 mg/kg/day amoxicillin + 6.4 mg/kg/day clavulanate divided twice daily for 10-14 days. 1, 4
• This is strongly recommended as first-line therapy for pediatric sinusitis. 1
• Reassess at 72 hours; lack of improvement warrants diagnostic reconsideration or escalation. 1

Community-Acquired Pneumonia

• Children < 5 years (outpatient): 90 mg/kg/day amoxicillin component divided twice daily for 10 days. 1
• Children < 3 years without risk factors: Consider amoxicillin alone at 80-100 mg/kg/day in 3 divided doses first; add clavulanate if treatment fails. 1
• Children with incomplete Hib vaccination or concurrent purulent otitis media: Use 80-90 mg/kg/day amoxicillin-clavulanate from the start. 1

Minimum Age Restriction

• Amoxicillin-clavulanate is approved for children ≥ 3 months of age. 1
• For infants < 3 months with suspected serious bacterial infection, use intravenous regimens (ampicillin + gentamicin or cefotaxime) instead. 1
• Safety and pharmacokinetic data are robust only after 3 months of age due to immature clavulanate metabolism in neonates. 1

Intravenous Dosing for Severe Infections

• All pediatric ages: 30 mg/kg three times daily IV. 1
• Switch to oral formulation as soon as clinically appropriate. 4

Treatment Duration by Indication

• Acute otitis media: 10 days (especially for children < 6 years). 1, 2
• Acute bacterial rhinosinusitis: 10-14 days for children; 5-7 days may suffice for adults. 1, 4
• Community-acquired pneumonia: 10 days. 1
• Continue therapy for 7 days after the patient becomes free of signs and symptoms. 1

Critical Prescribing Pitfalls to Avoid

• Verify suspension concentration (125/31 vs. 250/62) before calculating volume to prevent dosing errors. 1
• Using standard doses (45 mg/kg/day) when high-dose therapy is indicated leads to inevitable treatment failure with resistant organisms. 1
• The 14:1 ratio formulation causes significantly less diarrhea (12% vs. 31%) than older formulations with higher clavulanate content; always specify this ratio. 1, 5
• Most upper respiratory tract infections are viral; ensure the child meets criteria for bacterial infection (persistent symptoms > 10 days, severe symptoms, or "double sickening") before prescribing any antibiotic. 1

Renal Dose Adjustment

• In children with renal insufficiency, prolong the dosing interval according to creatinine clearance to avoid accumulation, as both amoxicillin and clavulanic acid are renally eliminated. 1

Adverse Effects

• Common: Diarrhea (25% vs. 15% placebo), nausea, vomiting, diaper dermatitis (51% vs. 35% placebo), and rash. 1, 2
• The high-dose 14:1 formulation has similar tolerability to conventional twice-daily formulations despite the higher amoxicillin dose. 6
• Serum levels of amoxicillin increase linearly with dose, and the difference in adverse effects between lower and higher doses is generally negligible. 1