Chapter 8. Dosage Calculations

Chapter 8. Dosage Calculations

 

Complete Chapter Questions With Answers

 

Sample Questions Are Posted Below

 

Multiple Choice

Identify the choice that best completes the statement or answers the question.

 

____     1.   The nurse provides a client with 20 mL of megestrol acetate (Megace 40 mg/mL strength) and the client reports, “I usually take one teaspoon of the long-acting formulation; are you sure this is the right stuff?” The nurse checks with the pharmacy and learns 5 mL of megestrol extended release (Megace ES 125 mg/mL) is equivalent to 800 mg of Megace. Which response by the nurse is best?

A.	“You are right; you should only take 5 mL of this medication.”
B.	“The two doses are equal since we don’t carry the long-acting medication.”
C.	“You should be taking 20 mL of medication at home as well.”
D.	“We will hold the medication at this time and verify the order with the physician.”

 

 

____     2.   A client admitted to the hospital with acute renal failure typically takes moexipril (Univasc) for hypertension. The client’s creatinine clearance is 32 mL/min and the pharmacy recommends a 50% dose reduction for this medication. The client’s typical dose is 7.5 mg. The nurse would expect the physician to order:

A.	3.75 mg
B.	2.25 mg
C.	4.25 mg
D.	5.75 mg

 

 

____     3.   The nurse is preparing potassium bicarbonate (TriLyte) for a pediatric client scheduled for a colonoscopy. The directions state to provide the prep at an estimated rate of 25 mL/kg/hr. The child weighs 55 lb. The nurse should encourage the child to drink how much of the solution each hour?

A.	1 cup
B.	2 cups
C.	2.5 cups
D.	4 cups

 

 

____     4.   The student nurse is preparing to give a client 20 mEq of potassium chloride (K-LOR). Directions say to mix the powdered medication with at least 4 oz of juice or water. The instructor would be satisfied with the student’s preparation if the student had which of the following?

A.	80 mL of apple juice
B.	120 mL of grape juice
C.	2/3 cup of water
D.	1 cup of fruit punch

 

Answer Section

 

MULTIPLE CHOICE

 

1. ANS:  B                    PTS:   1                    DIF:    Moderate

TOP:   Therapeutic Classification: Medication Administration      KEY:  Application

MSC:  NCLEX Category: Pharmacological Therapies

NOT:  See Dimensional Analysis (p. 128): 20 mL x 40 mg/mL is 800 mg Megace and is equivalent to 5 mL x 125 mg/mL or 625 mg of Megace ES. Because these two doses are reportedly equivalent and the client typically takes 1 teaspoon (5 mL) each day, the doses are equal and the client should be given the available formulation.

 

2. ANS:  A                    PTS:   1                    DIF:    Easy

TOP:   Therapeutic Classification: Medication Administration      KEY:  Application

MSC:  NCLEX Category: Pharmacological Therapies

NOT:  See Fraction Method (p. 131): 7.5 mg should be divided in half for a 50% reduction, resulting in 3.75 mg.

 

3. ANS:  C                    PTS:   1                    DIF:    Moderate

TOP:   Therapeutic Classification: Medication Administration      KEY:  Application

MSC:  NCLEX Category: Pharmacological Therapies

NOT:  See Calculating Pediatric Dosages (p. 133): 55 lb x 0.45 is 24.75 kg x 25 mL equals 618.75 mg, which is closest to 2.5 cups (600 mL). Note 1 cup is equal to 240 mL.

 

4. ANS:  B                    PTS:   1                    DIF:    Easy

TOP:   Therapeutic Classification: Medication Administration      KEY:  Application

MSC:  NCLEX Category: Pharmacological Therapies

NOT:  See Reconstituting powders (p. 135): 4 oz is equivalent to 120 mL.