A medication is ordered 1.5 mg/kg per dose every 8 hours. If patient weighs 9 kg, per-dose amount?

A medication is ordered 1.5 mg/kg per dose every 8 hours. If patient weighs 9 kg, per-dose amount?

• A. 27 mg
• B. 13.5 mg
• C. 9 mg
• D. 67.5 mg

Answer: (B)

To find the per-dose amount, multiply the patient’s weight in kilograms by the dose per kilogram. With 9 kg and 1.5 mg/kg per dose, calculate 9 × 1.5 = 13.5 mg. So each dose is 13.5 mg. The every-8-hours schedule doesn’t change the per-dose amount; it just tells you there are three doses in a 24-hour period, which would amount to 13.5 mg × 3 = 40.5 mg per day. The other numbers would come from using a different mg/kg value or a different weight, but with the given data, 13.5 mg is correct.

To find the per-dose amount, multiply the patient’s weight in kilograms by the dose per kilogram. With 9 kg and 1.5 mg/kg per dose, calculate 9 × 1.5 = 13.5 mg. So each dose is 13.5 mg. The every-8-hours schedule doesn’t change the per-dose amount; it just tells you there are three doses in a 24-hour period, which would amount to 13.5 mg × 3 = 40.5 mg per day. The other numbers would come from using a different mg/kg value or a different weight, but with the given data, 13.5 mg is correct.