Calculation scenario: A patient weighs 25 kg and is prescribed 4 mg/kg. What is the total dose?

Calculation scenario: A patient weighs 25 kg and is prescribed 4 mg/kg. What is the total dose?

• A. 100 mg
• B. 75 mg
• C. 125 mg
• D. 150 mg

Answer: (A)

Weight-based dosing uses the patient’s weight in kilograms to determine the total amount of drug in milligrams by multiplying the mg per kilogram by the weight. For this patient, 25 kg times 4 mg/kg equals 100 mg. The mg/kg unit times kg simplifies to mg, giving the total dose in milligrams. So the correct total dose is 100 mg. If the per-kilogram dose were different, other totals would reflect that: 3 mg/kg would give 75 mg, 5 mg/kg would give 125 mg, and 6 mg/kg would give 150 mg. Always confirm both the weight in kilograms and the prescribed mg/kg.

Weight-based dosing uses the patient’s weight in kilograms to determine the total amount of drug in milligrams by multiplying the mg per kilogram by the weight. For this patient, 25 kg times 4 mg/kg equals 100 mg. The mg/kg unit times kg simplifies to mg, giving the total dose in milligrams.

So the correct total dose is 100 mg. If the per-kilogram dose were different, other totals would reflect that: 3 mg/kg would give 75 mg, 5 mg/kg would give 125 mg, and 6 mg/kg would give 150 mg. Always confirm both the weight in kilograms and the prescribed mg/kg.