What is the appropriate pediatric dose of Augmentin (amoxicillin/clavulanate) for a child weighing 12.7 kg?

Augmentin Dosing for a 12.7 kg Child

For a child weighing 12.7 kg, the recommended dose of Augmentin is 571.5 mg of the amoxicillin component twice daily (90 mg/kg/day divided into 2 doses), which equals approximately 7.2 mL of the 400 mg/5 mL suspension twice daily for most respiratory tract infections. 1, 2

Weight-Based Calculation

• The high-dose regimen of 90 mg/kg/day is the standard recommendation for pediatric respiratory infections, particularly for children with risk factors such as age <2 years, daycare attendance, recent antibiotic use, or geographic areas with high pneumococcal resistance. 1, 2

• For this 12.7 kg child: 12.7 kg × 90 mg/kg/day = 1,143 mg total daily dose, administered as 571.5 mg every 12 hours. 1, 2

• Using the 400 mg/5 mL suspension (ES-600 formulation): 571.5 mg ÷ 400 mg × 5 mL = 7.14 mL per dose, rounded to 7.2 mL twice daily. 3

Indication-Specific Dosing Algorithm

High-Dose Regimen (90 mg/kg/day in 2 doses)

Use this regimen if ANY of the following apply:

• Child is <2 years old 2
• Daycare attendance 2
• Recent antibiotic use within the past 30 days 2
• Incomplete Haemophilus influenzae type b vaccination 2
• Geographic area with >10% penicillin-resistant S. pneumoniae 2
• Moderate-to-severe illness at presentation 2
• Community-acquired pneumonia 1, 2
• Acute otitis media in children <2 years 2
• Recurrent or persistent acute otitis media 4, 5

Standard-Dose Regimen (45 mg/kg/day in 2 doses)

• For children ≥2 years without the above risk factors and with less severe infections 3
• For this 12.7 kg child: 45 mg/kg/day = 571.5 mg daily = 285.75 mg (≈3.6 mL of 400 mg/5 mL suspension) twice daily 3

Formulation Selection

• The 400 mg/5 mL (ES-600) suspension provides a 14:1 ratio of amoxicillin to clavulanate (90 mg/kg amoxicillin with 6.4 mg/kg clavulanate), which minimizes diarrhea while maintaining efficacy against β-lactamase-producing organisms. 2, 5

• The FDA label confirms that for children ≥3 months, the every 12-hour regimen is recommended because it is associated with significantly less diarrhea than three-times-daily dosing. 3, 6

• Do not use the 125 mg/5 mL or 250 mg/5 mL suspensions for high-dose therapy, as they cannot achieve 90 mg/kg/day without excessive clavulanate. 3

Treatment Duration and Monitoring

• Standard duration is 10 days for acute otitis media, community-acquired pneumonia, and most respiratory infections. 1, 2, 3

• Clinical improvement should occur within 48–72 hours; if no improvement or worsening is observed, reevaluate the diagnosis and consider switching antibiotics or investigating for complications. 1, 2

• Fever typically resolves within 24–48 hours for pneumococcal infections, though cough may persist longer. 1

Maximum Dosing Limits

• Maximum single dose: 2,000 mg of amoxicillin per administration, regardless of weight. 2

• Maximum daily dose: 4,000 mg of amoxicillin per day. 1, 2

• For this 12.7 kg child, the calculated dose (571.5 mg twice daily) is well below these limits. 1, 2

Common Pitfalls to Avoid

• Do not substitute two 250 mg/125 mg tablets for one 500 mg/125 mg tablet, as they contain different amounts of clavulanate and are not equivalent. 3

• Verify the suspension concentration before dispensing (125/31,250/62, or 400/57 mg per 5 mL) to avoid dosing errors. 2, 3

• Do not use the 250 mg/125 mg tablets in children <40 kg due to incorrect amoxicillin-to-clavulanate ratios. 3

• Ensure the child is ≥3 months old before prescribing Augmentin; for infants <3 months, intravenous regimens (ampicillin + gentamicin) are preferred. 2, 3

Rationale for High-Dose Therapy

• The 90 mg/kg/day regimen achieves middle-ear and sinus fluid concentrations sufficient to overcome penicillin-resistant S. pneumoniae with MICs up to 2–4 mg/L. 2, 4

• High-dose amoxicillin/clavulanate provides coverage against β-lactamase-producing H. influenzae (58–82% of isolates) and M. catarrhalis, which are resistant to amoxicillin alone. 2, 7, 4

• Clinical trials demonstrate 76–95% clinical response rates and high bacteriologic eradication rates (approaching 100%) with the high-dose formulation. 2, 4

Adverse Effects

• The most common adverse effect is diarrhea (7.2% with twice-daily dosing vs. 10.7% with three-times-daily dosing). 6

• Other gastrointestinal disturbances include nausea and vomiting. 1, 2

• The high-dose formulation (90/6.4 mg/kg/day) shows similar tolerability to conventional formulations despite the higher amoxicillin dose. 4, 5