What is the recommended dose of amoxicillin-clavulanate (Amox-Clav) for the treatment of otitis media?

Amoxicillin-Clavulanate Dosing for Otitis Media

For acute otitis media, 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) divided into 2 doses daily for children, or 2000 mg amoxicillin/125 mg clavulanate twice daily for adults. 1

Pediatric Dosing

Standard High-Dose Regimen

• The recommended dose is 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate, given in 2 divided doses, using the 14:1 ratio formulation. 1
• Maximum single dose of amoxicillin is 2000 mg per dose. 1
• This high-dose regimen achieves middle ear fluid concentrations exceeding the minimum inhibitory concentration for approximately 87% of Streptococcus pneumoniae isolates, including intermediately resistant strains. 1

When to Use Amoxicillin-Clavulanate as First-Line

• Use amoxicillin-clavulanate instead of amoxicillin alone if the child received amoxicillin within the previous 30 days. 1
• Use amoxicillin-clavulanate if concurrent purulent conjunctivitis is present, as this indicates likely β-lactamase-producing organisms (Moraxella catarrhalis or Haemophilus influenzae). 1
• Children younger than 2 years or those attending daycare should receive amoxicillin-clavulanate due to increased risk of resistant organisms. 1

Treatment Duration

• Treat for 10 days in children, particularly those under 2 years of age. 1
• Clinical improvement should be evident within 48-72 hours; if not, reassess for treatment failure. 1

Adult Dosing

Standard Regimen

• Adults should receive amoxicillin-clavulanate 2000 mg/125 mg twice daily (or the standard 3 g/day total amoxicillin dose in combination with clavulanic acid). 2, 3
• Amoxicillin-clavulanate is preferred over amoxicillin alone as first-line therapy because it provides coverage against β-lactamase-producing organisms, which cause 17-34% of H. influenzae and 100% of M. catarrhalis infections. 3

Treatment Duration

• Adults can be treated with a shorter 5-7 day course for uncomplicated cases, based on IDSA guidelines for upper respiratory tract infections. 2, 3
• Reassess at 48-72 hours if symptoms worsen or fail to improve. 3

Critical Formulation Details

The 14:1 Ratio Advantage

• The 14:1 ratio formulation (90 mg/kg amoxicillin with 6.4 mg/kg clavulanate) is critical because it minimizes gastrointestinal side effects, particularly diarrhea, compared to older formulations with higher clavulanate ratios. 1
• Studies show reduced-concentration clavulanate (as low as 2.85 mg/kg/day) maintains efficacy while reducing diaper dermatitis rates from 33% to 21%. 4
• Twice-daily dosing causes less diarrhea than three-times-daily dosing while maintaining equivalent efficacy. 5, 6

Bacteriologic Efficacy

• High-dose amoxicillin-clavulanate demonstrates superior bacterial eradication: 96% for S. pneumoniae (including penicillin-resistant strains with MIC ≤2.0 μg/mL) compared to 80.4% with azithromycin. 1
• Coverage includes β-lactamase-producing H. influenzae and M. catarrhalis, which are the primary causes of treatment failure with amoxicillin alone. 3

Management of Treatment Failure

• If no improvement occurs within 48-72 hours, switch to ceftriaxone 50 mg/kg IM/IV (maximum 1-2 g) for 1-3 doses. 1, 3
• Treatment failure is defined as worsening condition, persistence of symptoms beyond 48 hours, or recurrence within 4 days of completing therapy. 3
• Do not simply extend the duration of the failing antibiotic; change to a different agent. 3

Common Pitfalls to Avoid

• Avoid using older amoxicillin-clavulanate formulations with higher clavulanate ratios (7:1 or 4:1), as these cause significantly more diarrhea. 1
• Do not underdose the amoxicillin component when treating potentially resistant organisms—the 90 mg/kg/day dose is essential for adequate middle ear penetration. 1
• Do not confuse otitis media with effusion (OME) for acute otitis media—isolated middle ear fluid without acute inflammation does not require antibiotics. 3
• Isolated redness of the tympanic membrane with normal landmarks is not an indication for antibiotic therapy. 3