An infant is prescribed amoxicillin 80 mg/kg/day to be given in two divided doses. The infant weighs 19.2 lb. The suspension is 250 mg/mL. How many milliliters are required for one dose?

An infant is prescribed amoxicillin 80 mg/kg/day to be given in two divided doses. The infant weighs 19.2 lb. The suspension is 250 mg/mL. How many milliliters are required for one dose?

• A. 0.8 mL
• B. 1.4 mL
• C. 1.6 mL
• D. 2.0 mL

Answer: (B)

Calculating the correct administration volume for a pediatric dose requires converting weight to kilograms, applying mg/kg/day to get the total daily amount, splitting that into two doses, and then converting the dose from milligrams to milliliters using the suspension strength. Weight in kg: 19.2 lb ÷ 2.2046 ≈ 8.71 kg. Total daily dose: 80 mg/kg/day × 8.71 kg ≈ 697 mg/day. Per-dose amount (two divided doses): 697 mg ÷ 2 ≈ 348.5 mg per dose. Volume per dose: 348.5 mg ÷ 250 mg/mL ≈ 1.394 mL, which rounds to about 1.4 mL per dose.

Calculating the correct administration volume for a pediatric dose requires converting weight to kilograms, applying mg/kg/day to get the total daily amount, splitting that into two doses, and then converting the dose from milligrams to milliliters using the suspension strength.

Weight in kg: 19.2 lb ÷ 2.2046 ≈ 8.71 kg.

Total daily dose: 80 mg/kg/day × 8.71 kg ≈ 697 mg/day.

Per-dose amount (two divided doses): 697 mg ÷ 2 ≈ 348.5 mg per dose.

Volume per dose: 348.5 mg ÷ 250 mg/mL ≈ 1.394 mL, which rounds to about 1.4 mL per dose.