What volume in ml of a 400 mg/5ml amoxicillin solution contains 875 mg?

Calculating Amoxicillin Dosage Volume

To administer 875 mg of amoxicillin from a 400 mg/5 mL solution, you need to give 10.9 mL of the solution.

Calculation Method

The calculation for determining the correct volume follows a simple proportion formula:

• Given information:

  • Desired dose: 875 mg amoxicillin
  • Solution concentration: 400 mg per 5 mL

• Step-by-step calculation:

  1. Set up the proportion: 400 mg : 5 mL = 875 mg : x mL
  2. Solve for x: x = (875 mg × 5 mL) ÷ 400 mg
  3. x = 4375 ÷ 400 = 10.9375 mL
  4. Round to practical measurement: 10.9 mL

Practical Administration Tips

• Use an oral syringe with clear markings to ensure accurate measurement
• For pediatric patients, verify that the calculated dose is appropriate for the child's weight
• The full volume (10.9 mL) may be large for a single administration, especially for children
• Consider checking the calculation with another healthcare provider for high-risk medications

Clinical Context

• Amoxicillin 875 mg is a standard adult dose used for various infections 1, 2
• The FDA-approved amoxicillin oral suspension comes in concentrations of 125 mg/5 mL, 250 mg/5 mL, and 400 mg/5 mL 2
• When administering liquid medications, accuracy is essential to ensure therapeutic efficacy and avoid toxicity

Common Pitfalls to Avoid

• Double-check your math to prevent dosing errors
• Avoid using household spoons for measurement as they are not standardized
• Ensure the concentration of the solution matches what was used in the calculation (400 mg/5 mL)
• Verify that the patient can tolerate the full volume of medication

Remember that accurate dosing of antibiotics is critical for achieving therapeutic outcomes and preventing antimicrobial resistance.