Clarification on Amoxicillin Suspension Dosing
I apologize for any confusion in my previous responses. For an 8.1 kg child with acute otitis media, the correct dose using high-dose amoxicillin (80-90 mg/kg/day) divided twice daily is approximately 7.3 mL of 250 mg/5 mL suspension per dose, given every 12 hours.
Calculation Breakdown
Let me walk through the precise calculation to eliminate ambiguity:
Target dose: 80-90 mg/kg/day 1
- For 8.1 kg: 648-729 mg/day total
- Divided into 2 doses: 324-365 mg per dose
Using 250 mg/5 mL suspension:
- For 365 mg per dose: (365 mg ÷ 250 mg) × 5 mL = 7.3 mL per dose
- For 324 mg per dose: (324 mg ÷ 250 mg) × 5 mL = 6.5 mL per dose
The discrepancy between 6.5 mL and 8.5 mL likely stems from:
- Different concentration suspensions (125 mg/5 mL vs 250 mg/5 mL) 2
- Rounding to the higher end (90 mg/kg) vs lower end (80 mg/kg) of the recommended range
- Calculation errors in previous responses
Practical Recommendation
Use 7 mL of 250 mg/5 mL suspension twice daily (every 12 hours), which provides approximately 700 mg/day or 86 mg/kg/day—squarely within the guideline-recommended range 1.
Important Considerations:
- Always verify the suspension concentration on the bottle label before dosing 2
- Use a calibrated oral syringe for accurate measurement 2
- The 250 mg/5 mL concentration is more practical for this weight range, requiring smaller volumes
- If using 125 mg/5 mL suspension instead, you would need approximately 14 mL per dose to achieve the same total daily dose
Common Pitfall to Avoid:
The most frequent dosing error occurs when providers fail to confirm which suspension concentration was dispensed by the pharmacy. A dose calculated for 250 mg/5 mL suspension will result in significant underdosing if 125 mg/5 mL is actually dispensed 2.