What is the total daily dose of amoxicillin (amoxicillin) in milligrams if 10 mL of amoxicillin 400 mg/5 mL is taken twice daily?

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Last updated: September 12, 2025View editorial policy

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Calculation of Total Daily Amoxicillin Dose

The total daily dose of amoxicillin when given as 10 mL of amoxicillin 400 mg/5 mL twice daily is 1600 mg per day.

Step-by-Step Calculation

To determine the total daily dose of amoxicillin in this scenario, we need to follow a systematic approach:

  1. Identify the concentration: 400 mg per 5 mL
  2. Calculate the amount in each dose: 10 mL contains 800 mg
    • 400 mg/5 mL × 10 mL = 800 mg per dose
  3. Calculate the daily dose: 800 mg × 2 times daily = 1600 mg per day

Verification and Context

This dosing can be verified against standard dosing guidelines for amoxicillin:

  • According to guidelines, amoxicillin dosing typically ranges from 750 to 1750 mg/day in divided doses every 8 to 12 hours for adults 1.
  • For pediatric patients, dosing ranges from 20 to 45 mg/kg/day in divided doses every 8 to 12 hours 1.
  • The dose of 1600 mg/day falls within the recommended range for adults.

Clinical Implications

  • This dose (1600 mg/day) is appropriate for treating many common infections:
    • For uncomplicated urinary tract infections, amoxicillin 500 mg PO/IV every 8 hours (1500 mg/day) is recommended 2.
    • For streptococcal pharyngitis, amoxicillin 50 mg/kg once daily (maximum = 1000 mg) or 25 mg/kg twice daily (maximum = 500 mg) for 10 days is recommended 2.

Common Pitfalls to Avoid

  • Calculation errors: Always double-check your math when calculating medication doses.
  • Concentration confusion: Be careful to note the exact concentration (400 mg/5 mL in this case).
  • Frequency misinterpretation: "Twice daily" means the total daily dose is 2 times the single dose.
  • Unit conversion errors: Ensure all units are consistent (mg, mL) throughout calculations.

Important Considerations

  • For pediatric patients, it's essential to verify that the calculated dose is appropriate for the child's weight.
  • The total daily dose of 1600 mg is within the therapeutic range for most indications in adults.
  • For specific infections like H. pylori, higher doses may be required (e.g., 1 gram amoxicillin twice daily) 1.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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