What is the recommended oral dosing regimen of amoxicillin‑clavulanate (Augmentin) for a child, including weight‑based dose, dosing frequency, treatment duration, and alternatives for intolerance or severe penicillin allergy?

Oral Dosing of Amoxicillin-Clavulanate (Augmentin) in Children

For most pediatric bacterial infections requiring amoxicillin-clavulanate, prescribe 90 mg/kg/day of the amoxicillin component with 6.4 mg/kg/day of clavulanate, divided into 2 doses (maximum 4000 mg/day), using the 14:1 ratio formulation. 1, 2

Weight-Based Dosing Algorithm

Standard High-Dose Regimen (First-Line)

• Calculate the amoxicillin component at 90 mg/kg/day divided into 2 doses for acute otitis media, community-acquired pneumonia, acute bacterial sinusitis, and other respiratory tract infections. 1, 2
• The clavulanate component should be 6.4 mg/kg/day, creating a 14:1 amoxicillin-to-clavulanate ratio that minimizes diarrhea compared to other formulations. 1, 2
• Maximum daily dose is 4000 mg of amoxicillin regardless of weight. 3, 2

Alternative Standard-Dose Regimen

• For mild infections without risk factors for resistant organisms, 45 mg/kg/day of amoxicillin component divided into 3 doses OR 90 mg/kg/day in 2 doses may be used. 3, 2
• This lower-dose approach is not recommended for acute otitis media, pneumonia, or when β-lactamase-producing organisms are suspected. 1

Dosing Frequency and Duration

Frequency

• Administer twice daily (every 12 hours) for the high-dose 90/6.4 mg/kg/day regimen. 1, 2
• Three-times-daily dosing may be used for the 45 mg/kg/day regimen but has higher rates of diarrhea and lower adherence. 2

Duration

• 10 days for acute otitis media in children under 6 years. 1, 2
• 10 days for community-acquired pneumonia. 3, 2, 4
• 10-14 days for acute bacterial rhinosinusitis. 2
• Clinical improvement should occur within 48-72 hours; if not, reassess the diagnosis and consider treatment failure. 3, 2

Indications for High-Dose Therapy

Use the 90/6.4 mg/kg/day regimen when any of the following risk factors are present: 1, 2

• Age < 2 years
• Daycare attendance
• Recent antibiotic use within the past 30 days
• Concurrent purulent conjunctivitis (otitis-conjunctivitis syndrome)
• Incomplete Haemophilus influenzae type b vaccination (< 3 doses)
• Geographic area with > 10% penicillin-resistant Streptococcus pneumoniae
• Moderate to severe illness at presentation
• Treatment failure after 48-72 hours of amoxicillin alone

Alternatives for Penicillin Allergy

Non-Anaphylactic (Type IV) Reactions

• Cefdinir 14 mg/kg/day in 1-2 doses 1
• Cefuroxime 30 mg/kg/day in 2 doses 1
• Cefpodoxime 10 mg/kg/day in 2 doses 1
• These cephalosporins have distinct chemical structures with minimal cross-reactivity risk (historically overestimated at 10%, actually < 2%). 1

Type I (IgE-Mediated/Anaphylactic) Reactions

• Azithromycin 12 mg/kg once daily for 5 days (inferior bacteriologic efficacy) 3
• Clindamycin 30-40 mg/kg/day in 3 doses with or without a third-generation cephalosporin 1
• Levofloxacin or moxifloxacin for severe infections in older children (use with caution due to musculoskeletal concerns) 3

Severe Penicillin Allergy with Treatment Failure

• Ceftriaxone 50 mg/kg IM or IV daily for 1-3 days 1
• Consider tympanocentesis if skilled, or refer to otolaryngology for drainage and culture. 1

Age Restrictions and Safety

• Minimum age: ≥ 3 months for routine oral amoxicillin-clavulanate use. 2
• For infants < 3 months with suspected serious bacterial infection, use IV ampicillin + gentamicin or cefotaxime instead of oral therapy. 2
• Safety and pharmacokinetic data are robust only after 3 months of age when clavulanate metabolism is reliable. 2

Common Pitfalls to Avoid

Underdosing Errors

• Verify the suspension concentration (125/31 mg per 5 mL vs. 250/62 mg per 5 mL vs. 600/42.9 mg per 5 mL) before calculating volume to prevent dosing errors. 2
• Using standard-dose formulations (40-45 mg/kg/day) when high-dose therapy is indicated leads to treatment failure with resistant organisms. 2

Inappropriate Use

• Do not prescribe for viral upper respiratory infections; approximately 70% of pediatric sore throats are viral and do not require antibiotics. 3
• Isolated tympanic membrane redness without bulging or effusion does not meet criteria for bacterial otitis media. 2

Monitoring Failures

• Reassess at 48-72 hours if symptoms persist or worsen; fever should resolve within 24-48 hours for pneumococcal infections. 3, 2
• If no improvement occurs, consider atypical pathogens (especially in children ≥ 5 years), treatment failure, or complications. 3, 4

Practical Dosing Examples

Example 1: 18 kg Child with Acute Otitis Media

• 18 kg × 90 mg/kg/day = 1620 mg/day ÷ 2 = 810 mg twice daily
• Using 600 mg/5 mL suspension: 810 mg ÷ 120 mg/mL = 6.75 mL twice daily 2

Example 2: 25 kg Child with Community-Acquired Pneumonia

• 25 kg × 90 mg/kg/day = 2250 mg/day ÷ 2 = 1125 mg twice daily
• Duration: 10 days 3, 2, 4

Example 3: 40 kg Adolescent

• Dose as an adult using standard adult formulations (e.g., 2000 mg twice daily of extended-release formulation). 3

Rationale for High-Dose Regimen

• Achieves middle-ear fluid and lung tissue concentrations that overcome penicillin-resistant S. pneumoniae with MICs of 2-4 mg/L. 1, 5, 6
• Eradication rates of 96% for S. pneumoniae and near 100% for β-lactamase-producing H. influenzae and M. catarrhalis. 1, 5
• Maintains plasma concentrations above MIC for ≥ 34% of the dosing interval, the threshold for bacteriologic efficacy. 6
• The 14:1 ratio formulation causes significantly less diarrhea (25% vs. 35-40% with older formulations) while maintaining superior efficacy. 2, 5