A medication is dosed at 2 mg/kg. The patient weighs 3.5 kg. What is the dose?

A medication is dosed at 2 mg/kg. The patient weighs 3.5 kg. What is the dose?

• A. 5 mg
• B. 6 mg
• C. 7 mg
• D. 9 mg

Answer: (C)

To find a weight-based dose, multiply the dose per unit weight by the patient’s weight in the same weight unit. Here, 2 mg per kg times 3.5 kg gives 7 mg. The units mg/kg × kg cancel to mg, so the total dose is 7 mg. If weight weren’t in kilograms, you’d convert first (1 kg = 2.2046 lb).

To find a weight-based dose, multiply the dose per unit weight by the patient’s weight in the same weight unit. Here, 2 mg per kg times 3.5 kg gives 7 mg. The units mg/kg × kg cancel to mg, so the total dose is 7 mg. If weight weren’t in kilograms, you’d convert first (1 kg = 2.2046 lb).