Amoxicillin Suspension Dose Calculation
To deliver 1000 mg of amoxicillin from a 400 mg/5 mL suspension, administer 12.5 mL.
Calculation Method
The calculation follows a straightforward proportion:
- Concentration: 400 mg per 5 mL 1
- Desired dose: 1000 mg
- Formula: (1000 mg ÷ 400 mg) × 5 mL = 12.5 mL
Verification
- 400 mg/5 mL = 80 mg/mL concentration 1
- 1000 mg ÷ 80 mg/mL = 12.5 mL
Clinical Context
Standard amoxicillin suspension concentrations vary, and accurate measurement is essential for therapeutic efficacy 1. The FDA-approved amoxicillin formulations include suspensions at 6 mg/mL (reconstituted from powder), but the 400 mg/5 mL concentration (equivalent to 80 mg/mL) represents a higher-strength formulation 1.
Dosing Considerations
- Adult dosing for most infections typically ranges from 250-500 mg three times daily or 500-875 mg twice daily 1
- 1000 mg doses are used for specific indications, including high-dose regimens for resistant organisms or as part of Helicobacter pylori eradication therapy (1 g twice daily) 2
- Absorption characteristics: Amoxicillin demonstrates non-linear absorption kinetics at higher doses, with saturable absorption mechanisms 3
Administration Guidance
- Timing: Amoxicillin can be administered without regard to meals, though administration with food may improve gastrointestinal tolerability 1
- Measurement: Use calibrated measuring devices (oral syringes or dosing cups) rather than household spoons to ensure accurate dosing 1
- Storage: Reconstituted suspensions require refrigeration and have limited stability (typically 14 days); verify manufacturer's storage requirements 1