Dosage by Patient Weight

Medication doses are often based on the patient's body weight, especially with infants and children. Although this is primarily a professional responsibility, you may use the manufacturer's recommendations to determine if a prescribed dose is a reasonable dose to administer.

Example 1

The manufacturer's recommendation for pediatric Tylenol is 10 mg/kg/dose. How many mg are recommended for each dose for a 20 kg child?

10 mg x

20 = 200 mg 1 1

Example 2

The recommendation for Garamycin is 2 mg/kg/dose. The child weighs 15 kg. The Garamycin is supplied 10 mg/ml. How many ml will provide the recommended dose?

1. How many mg are recommended for each dose for a 15 kg child?

2 mg x

15 = 30 mg 1 1 2. How many ml are required for a single dose?

1 ml x

30 = 3 ml 10 1 Therefore, 3 ml will provide the recommended dose for a 15 kg child.

Example 3

The order is for Depakene 15mg/kg/day for a patient who weighs 110 pounds. The medication is to be given in 3 divided doses. Depakene is stocked in 125 mg/capsules. Calculate the number of capsules to give per dose.

a. Convert the patient's body weight to kilograms.

1 kg x

110 = 50 kg 2.2 1 b. Calculate the dosage (per day) of medication based on the patient's body weight.

15 mg x

50 = 750 mg 1 1 c. Calculate the number of capsules to be administered per day.

1 capsule x

750 = 6 capsules 125 1 d. Calculate the number of capsules to be administered per dose.

6 capsule x

1 = 2 capsules/dose 1 3 doses This patient should receive three doses of 2 capsules per day