Dosage By Weight Questions
Given the weight of a patient and a dosage specified in terms of weight,
calculate the necessary dosage. These problems are a type of pediatric dosage calculations.
Formula:
Example: A doctor orders 200 mg of Rocephin to be taken by a
15.4 lb
infant every 8 hours. The medication label shows that
75150 mg/kg per day
is the appropriate dosage range. Is this doctor's order within the desired range?
Weight in Kg * Dosage Per Kg

= Y (Required Dosage)

Convert 15.4 lb to kg.
 lb → kg ( ÷ by 2.2 )
 15.4 lb ÷ 2.2 = 7 kg
7 kg * 75 mg/kg

= 525 mg (Minimum Desired Dosage)

7 kg * 150 mg/kg

= 1,050 mg (Maximum Desired Dosage)

24 hours in one day and the medication is ordered every 8 hours.
 24 hrs / 8 hrs = 3 times per day doctor ordered medication
 200 * 3 = 600 mg ordered per day
 600 mg is within the desired range of 5251,050 mg
Yes doctor has ordered a dosage within the desired range.
Example: Solumedrol
1.5 mg/kg is ordered for a child weighing
74.8 lb. Solumedrol is available as 125 mg / 2mL.
How many mL must the nurse administer?
Weight in Kg * Dosage Per Kg

= Y (Required Dosage)

Convert 74.8 lb to kg.
 lb → kg ( ÷ by 2.2 )
 74.8 lb ÷ 2.2 = 34 kg
34 kg * 1.5 mg/kg

= 51 mg


x Volume Per Have

= Y (Liquid Required)
