What is the appropriate amoxicillin‑clavulanate (Augmentin) dosing regimen for a child with acute otitis media and streptococcal pharyngitis?

Augmentin Dosing for Concurrent Otitis Media and Streptococcal Pharyngitis

For a child with both acute otitis media and strep pharyngitis, use high-dose amoxicillin-clavulanate at 90 mg/kg/day of the amoxicillin component with 6.4 mg/kg/day of clavulanate (14:1 ratio formulation) divided into 2 doses daily for 10 days. 1

Rationale for High-Dose Therapy

• High-dose amoxicillin-clavulanate provides optimal coverage for both conditions simultaneously, addressing Streptococcus pneumoniae (including penicillin-resistant strains), beta-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis in otitis media, while also covering Group A Streptococcus in pharyngitis 1, 2

• The 90 mg/kg/day dosing achieves middle ear fluid concentrations exceeding the minimum inhibitory concentration for approximately 87% of S. pneumoniae isolates, including intermediately resistant strains 1

• Clinical trials demonstrate 98% eradication of S. pneumoniae (including penicillin-resistant strains with MICs up to 4 mcg/mL) and 94% eradication of H. influenzae with this high-dose regimen 2

Specific Dosing Calculation

• Calculate the dose based on the amoxicillin component only: 90 mg/kg/day divided into 2 doses 1

• The 14:1 ratio formulation (Augmentin ES-600) provides 600 mg amoxicillin with 42.9 mg clavulanate per 5 mL 3

• Maximum single dose of amoxicillin is 2000 mg 1

• Example: A 20 kg child would receive 1800 mg amoxicillin daily = 900 mg (7.5 mL of ES-600) twice daily 1

Treatment Duration

• Treat for 10 days for children under 2 years or those with bilateral otitis media 1

• The 10-day duration is appropriate for both the otitis media and streptococcal pharyngitis components 1, 2

• Reassess at 48-72 hours if symptoms worsen or fail to improve 1

Critical Advantages of This Approach

• The 14:1 ratio formulation causes significantly less diarrhea than older 4:1 or 7:1 formulations, improving tolerability 1, 4

• Twice-daily dosing improves compliance compared to three-times-daily regimens, with equivalent efficacy 5, 6

• This single regimen eliminates the need for multiple antibiotics and simplifies the treatment plan 1

Common Pitfalls to Avoid

• Do not use standard-dose amoxicillin-clavulanate (45 mg/kg/day) when treating otitis media in the current era of resistant organisms—this is inadequate dosing 1

• Do not prescribe the older 7:1 ratio formulations when high-dose therapy is indicated; only the 14:1 ratio (ES-600) provides 90 mg/kg/day of amoxicillin with acceptable clavulanate levels 1, 4

• Avoid calculating the dose based on the clavulanate component—always base calculations on the amoxicillin component 1

• Do not extend treatment beyond 10 days unless there is documented treatment failure requiring a switch to alternative therapy 1

Management of Treatment Failure

• If no improvement occurs within 48-72 hours, switch to ceftriaxone 50 mg/kg IM/IV for 1-3 days (maximum 1-2 grams) 1

• Treatment failure is defined as worsening symptoms, persistence beyond 48 hours, or recurrence within 4 days of completing therapy 7