Amoxicillin Dosing for a 173.2 lb Patient
For a patient weighing 173.2 lbs (78.6 kg), the recommended amoxicillin dose at 80-90 mg/kg/day would be 6,288-7,074 mg per day, which should be divided into 2-3 doses.
Calculation and Dosing Recommendation
Convert weight from pounds to kilograms:
- 173.2 lbs = 78.6 kg
Calculate total daily dose:
- At 80 mg/kg/day: 80 mg/kg × 78.6 kg = 6,288 mg/day
- At 90 mg/kg/day: 90 mg/kg × 78.6 kg = 7,074 mg/day
Dosing schedule:
- Divided into 2-3 doses per day (every 8-12 hours)
- For twice daily dosing: 3,144-3,537 mg every 12 hours
- For three times daily dosing: 2,096-2,358 mg every 8 hours
Clinical Considerations
This high-dose amoxicillin regimen (80-90 mg/kg/day) is typically used for:
- Severe infections
- Infections in areas with high prevalence of drug-resistant organisms
- Specific conditions like pneumonia in children 1
Standard adult dosing for amoxicillin is typically lower (750-1750 mg/day) 2, but higher doses are warranted in specific clinical scenarios requiring increased coverage.
The FDA label for amoxicillin indicates that adult dosing ranges from 750 to 1750 mg/day in divided doses every 8 to 12 hours 2, but clinical guidelines support higher dosing in specific situations.
Important Considerations
Renal function should be assessed before administering this dose, as dose reduction is necessary for patients with severe renal impairment (GFR >30 mL/min) 2.
The calculated dose exceeds typical adult maximum doses, so consider rounding to a practical dosing regimen using available formulations (250 mg, 500 mg tablets or 125 mg/5 mL, 250 mg/5 mL suspensions).
For practical administration, consider:
- 3,000 mg twice daily (6,000 mg/day)
- 2,000 mg three times daily (6,000 mg/day)
Common Pitfalls to Avoid
Weight conversion errors: Always convert pounds to kilograms accurately (1 kg = 2.2 lbs).
Dosing frequency errors: High-dose amoxicillin should be divided into multiple daily doses to maintain therapeutic levels.
Failure to adjust for renal function: Patients with impaired renal function require dose adjustments.
Using patient-estimated weight: When possible, patients should be weighed rather than relying on self-reported weights, as studies show healthcare provider estimates can be off by more than 10% in about half of cases 3.