For a 15 kg patient, a prescribed dose is 1 mg/kg. If the concentration is 10 mg/mL, what volume in milliliters is required?

For a 15 kg patient, a prescribed dose is 1 mg/kg. If the concentration is 10 mg/mL, what volume in milliliters is required?

• A. 1.0 mL
• B. 1.5 mL
• C. 2.0 mL
• D. 2.5 mL

Answer: (B)

Weight-based dosing is turned into a total amount of drug, then converted to volume using the concentration. First, compute the total dose: 15 kg × 1 mg/kg = 15 mg. The concentration is 10 mg per 1 mL, so to get 15 mg you need 15 mg ÷ 10 mg/mL = 1.5 mL. Check the units: mg cancels, leaving mL. Quick sanity check: at 1 mL you’d deliver 10 mg; at 2 mL you’d deliver 20 mg, so 1.5 mL gives 15 mg. The required volume is 1.5 mL.

Weight-based dosing is turned into a total amount of drug, then converted to volume using the concentration. First, compute the total dose: 15 kg × 1 mg/kg = 15 mg. The concentration is 10 mg per 1 mL, so to get 15 mg you need 15 mg ÷ 10 mg/mL = 1.5 mL. Check the units: mg cancels, leaving mL. Quick sanity check: at 1 mL you’d deliver 10 mg; at 2 mL you’d deliver 20 mg, so 1.5 mL gives 15 mg. The required volume is 1.5 mL.