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 
75-150 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 525-1,050 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)
	 |