Chapter 5 Dosage Calculations

Chapter 5  Dosage Calculations

Complete Chapter Questions And Answers
 

Sample Questions

1.
The nurse is calculating a drug dosage and converting from milligrams to grams. What measurement system is the nurse using?
A)
Metric system
B)
Apothecary system
C)
Household system
D)
Avoirdupois system
Ans:
A

Feedback:

The metric system is the most widely used system of measurement in the world; it is based on the decimal system. The gram is the basic unit of solid measure, and the liter unit of liquid measure. The apothecary system uses the grain as the basic unit of solid measure. The household system uses the pound as the basic unit of measure. The avoirdupois system uses ounces and grains, but it is mostly used by drug manufacturers for bulk medications.

2.
The nurse teaches a young mother the importance of administering appropriate dosages of acetaminophen (Tylenol) and determines further teaching is needed when the mother makes what statement?
A)
“The children’s dosage will change with time as they grow.”
B)
“My baby’s dose of Tylenol is about 1 half an adult dose.”
C)
“It is important to give the right dose to prevent toxic effects of the medication.”
D)
“My children’s dose of Tylenol should be based on their weight or age.”
Ans:
B

Feedback:

A child’s dose is never based on an adult’s dose. A child’s dosage is based on weight and age and will change with age as they grow. Larger than directed dosages can result in toxic effects of this medication.

3.
A nurse calculates the pediatric patient’s medication dosage using Clark’s rule and uses what formula?
A)
Infant’s age in months/150 months times the average adult dose
B)
Child’s age in years/child’s age in years plus 12 times the average adult dose
C)
Weight of child in pounds/150 pounds times the average adult dose
D)
Surface area in square meters/1.73 times the average adult dose
Ans:
C

Feedback:

Clark’s rule uses the child’s weight to calculate the dose and assumes the adult dose is based on a 150-pound person. Fried’s rule applies to a child younger than 1 year of age and assumes that an adult dose would be appropriate for a child who is 12.5 years (150 months) old. Young’s rule applies to children 1 to 12 years of age. Surface area calculation of a child’s dose is determined with the use of a nomogram including the child’s height and weight.

4.
The nurse receives a new medication order for a patient to administer 240 mg of medication per day in equally divided doses every 6 hours. How many mg of the drug should the nurse administer for each dose?
Ans:
60 mg

Feedback:

Because there are 24 hours in a day, giving a drug every 6 hours would mean giving the drug 4 times a day. Because the total daily dose is 240 mg, dividing that dose by 4 would mean each dose should be 60 mg.

5.
A physician orders 500 mL of IV solution be administered over 8 hours. If the IV infusion set delivers 15 drops per mL, how many drops per minute should the nurse administer to the patient?
A)
15 drops/min
B)
20 drops/min
C)
32 drops/min
D)
64 drops/min
Ans:
A

Feedback:

If a patient was to receive 500 mL in 8 hours, dividing 500 by 8 would mean that the patient would receive 62.5 mL in 1 hour, or 60 min. Setting up the equation, 15 drops/mL/X equals 62.5 mL/60 min; cross-multiplying, the answer will be 15 drops/min.