Augmentin Dosing for a 6.58 kg Infant
For a 6.58 kg infant under 3 months of age, administer Augmentin 125 mg/5 mL suspension at 1 mL (30 mg amoxicillin component) every 12 hours. 1
Weight-Based Calculation
The FDA-approved dosing for neonates and infants aged <12 weeks (<3 months) is 30 mg/kg/day of the amoxicillin component, divided every 12 hours. 1
For this 6.58 kg infant: 6.58 kg × 30 mg/kg/day = 197.4 mg/day total, which equals 98.7 mg per dose (approximately 100 mg per dose) every 12 hours. 1
Using the 125 mg/5 mL suspension (which contains 25 mg amoxicillin per mL), the calculated volume is 4 mL per dose every 12 hours. 1
However, the FDA label specifically recommends using the 125 mg/5 mL formulation for this age group and states that experience with the 200 mg/5 mL formulation is limited in infants <12 weeks. 1
Critical Formulation Considerations
The 125 mg/5 mL oral suspension is the recommended formulation for infants under 3 months of age, as the FDA label explicitly states that "experience with the 200 mg/5 mL formulation in this age group is limited, and thus, use of the 125 mg/5 mL oral suspension is recommended." 1
The 250 mg suspension referenced in your question likely refers to a different concentration than what is FDA-approved for this age group. 1
Do not substitute different tablet or suspension strengths, as they contain different ratios of amoxicillin to clavulanate and are not interchangeable. 1
Administration Guidelines
Administer the suspension every 12 hours (twice daily) rather than every 8 hours, as the every-12-hour regimen is associated with significantly less diarrhea. 1
The medication can be given without regard to meals, though administration with food may improve gastrointestinal tolerability. 2
Use an appropriate measuring device such as a 3-mL or 5-mL oral syringe for accurate dosing in infants. 2
Duration of Therapy
For respiratory tract infections, the typical treatment duration is 7-10 days, with acute otitis media specifically requiring 10 days of treatment. 1, 3
Clinical improvement should be evident within 48-72 hours; if no improvement occurs or the infant's condition deteriorates, reevaluation and further investigation are necessary. 2, 4
Common Pitfalls to Avoid
Do not use the 250 mg/125 mg tablets or higher-concentration suspensions in infants under 3 months, as these formulations have different clavulanate ratios and are not appropriate for this age group. 1
Do not round up to adult or older pediatric dosing regimens (such as 45 mg/kg/day or 90 mg/kg/day), as these higher doses are only indicated for children ≥3 months of age. 3, 1
Ensure proper reconstitution of the powder suspension according to package instructions to achieve the correct final concentration of 125 mg/5 mL. 2