What is the maximum recommended dose of Augmentin (amoxicillin/clavulanate) for a 33‑kg child?

Maximum Augmentin Dose for a 33‑kg Child

For a 33‑kg child, the highest recommended dose of Augmentin is 2,970 mg/day of amoxicillin (90 mg/kg/day) combined with 211 mg/day of clavulanate (6.4 mg/kg/day), administered as 1,485 mg amoxicillin + 106 mg clavulanate twice daily. 1, 2

Weight‑Based Calculation

• Calculation: 33 kg × 90 mg/kg/day = 2,970 mg amoxicillin per day, divided into two doses of 1,485 mg each. 1, 2
• Clavulanate component: 33 kg × 6.4 mg/kg/day = 211 mg clavulanate per day, divided into two doses of 106 mg each. 1, 2
• This high‑dose regimen provides a 14:1 ratio of amoxicillin to clavulanate, which is the preferred formulation for resistant organisms. 2, 3

When to Use High‑Dose Therapy

High‑dose Augmentin (90 mg/kg/day amoxicillin component) is indicated when any of the following risk factors are present:

• Age < 2 years 1, 2
• Daycare attendance 1, 2
• Recent antibiotic use within the past 30 days 1, 2
• Moderate‑to‑severe illness at presentation 1, 2
• Geographic area with penicillin‑resistant Streptococcus pneumoniae prevalence > 10% 1, 2
• Incomplete Haemophilus influenzae type b vaccination 2
• Concurrent purulent otitis media or conjunctivitis 1, 2
• Treatment failure after 48–72 hours on standard‑dose amoxicillin 1, 2

Absolute Maximum Daily Dose

• The absolute maximum daily dose of amoxicillin for children is 4,000 mg/day, regardless of weight. 1, 4
• For a 33‑kg child, the calculated dose (2,970 mg/day) remains well below this ceiling. 1, 4
• Patients weighing ≥ 40 kg should be dosed according to adult recommendations (typically 875 mg/125 mg twice daily or 2,000 mg/125 mg twice daily for high‑dose therapy), not pediatric weight‑based calculations. 1, 5

Practical Formulation Selection

• For a 33‑kg child requiring high‑dose therapy, the 400 mg/57 mg per 5 mL oral suspension is the most practical formulation. 5
• Volume per dose: To deliver 1,485 mg amoxicillin, administer approximately 18.5 mL of the 400 mg/57 mg per 5 mL suspension twice daily. 5
• Alternative: The 600 mg/42.9 mg per 5 mL formulation (Augmentin ES‑600) can deliver 1,485 mg amoxicillin in approximately 12.4 mL twice daily. 3, 6

Treatment Duration

• For acute otitis media: 10 days is the recommended duration for children, particularly those < 6 years. 1, 5
• For acute bacterial rhinosinusitis: 10–14 days is recommended for children. 1
• For community‑acquired pneumonia: 10 days is the standard duration. 2

Clinical Reassessment

• Expect clinical improvement within 48–72 hours of initiating high‑dose therapy. 1, 2
• If no improvement or worsening occurs after 72 hours, consider switching to an alternative antibiotic (e.g., ceftriaxone), obtaining cultures, or performing imaging to rule out complications. 1

Safety and Tolerability

• The 14:1 ratio formulation (90/6.4 mg/kg/day) causes significantly less diarrhea than older 4:1 or 7:1 ratio formulations while maintaining equivalent efficacy. 2, 3, 7
• Diarrhea incidence: Approximately 9–10% with twice‑daily high‑dose therapy versus 27% with three‑times‑daily standard formulations. 8, 7
• Serum amoxicillin levels increase linearly with dose, and the difference in adverse effects between standard and high doses is generally negligible. 2, 4

Common Prescribing Pitfalls

• Do not use two 250 mg/125 mg tablets to substitute for one 500 mg/125 mg tablet, as the clavulanate content differs and this creates an incorrect ratio. 5
• Do not use adult 250 mg/125 mg tablets in children < 40 kg, as the amoxicillin‑to‑clavulanate ratio is inappropriate for pediatric dosing. 5
• Verify the suspension concentration before dispensing (125/31,250/62,400/57, or 600/42.9 mg per 5 mL) to avoid dosing errors. 2
• Administer at the start of meals to enhance clavulanate absorption and minimize gastrointestinal intolerance. 5