DOSAGE CALCULATIONS MADE
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1
Clinical Scenario: The healthcare provider prescribes
levothyroxine $125\text{ mcg}$ PO daily for a client with
hypothyroidism. The pharmacy supplies levothyroxine labeled
$0.125\text{ mg}$ per tablet. How many tablets will the nurse
administer?
A. 0.5 tablets
B. 1 tablet
C. 1.5 tablets
D. 2 tablets
Correct Answer: B
Rationale:
• Step 1 (Identify target): The goal is to find the number of
tablets to administer per dose ($\text{tablets/dose}$).
• Step 2 (Dimensional Analysis Setup): Convert the
prescribed micrograms ($\text{mcg}$) to milligrams
($\text{mg}$) to match the available unit, then solve for
tablets.
$$\frac{1\text{ tablet}}{0.125\text{ mg}} \times \frac{1\text{
mg}}{1,000\text{ mcg}} \times \frac{125\text{ mcg}}{1\text{
dose}}$$
, • Step 3 (Calculation & Solution):
$$\frac{125}{0.125 \times 1,000} = \frac{125}{125} = 1\text{
tablet per dose}$$
Medication Safety Note: Micrograms and milligrams are easily
confused. Always convert to a matching unit before dividing.
Levothyroxine is a narrow therapeutic index drug; a decimal
error can result in severe thyrotoxicosis or underdosing.
Question 2
Clinical Scenario: A provider orders potassium chloride liquid
$30\text{ mEq}$ PO twice daily for a client taking a loop
diuretic. The medication is supplied in a bottle labeled $20\text{
mEq}/15\text{ mL}$. How many milliliters should the nurse
administer per dose?
A. 10 mL
B. 15 mL
C. 22.5 mL
D. 30 mL
Correct Answer: C
Rationale:
• Step 1 (Identify target): Find the volume in milliliters
($\text{mL}$) required for the prescribed milliequivalents
($\text{mEq}$).
, • Step 2 (Dimensional Analysis Setup):
$$\frac{15\text{ mL}}{20\text{ mEq}} \times \frac{30\text{
mEq}}{1\text{ dose}}$$
• Step 3 (Calculation & Solution):
$$\frac{15 \times 30}{20} = \frac{450}{20} = 22.5\text{ mL}$$
Medication Safety Note: Liquid potassium chloride is highly
irritating to the gastrointestinal tract. The nurse should ensure
the client dilutes this volume in water or juice as directed to
prevent gastric mucosal injury.
Question 3
Clinical Scenario: The provider orders furosemide $40\text{
mg}$ intravenous push (IVP) stat for a client with acute
pulmonary edema. The vial on hand is labeled furosemide
$10\text{ mg}/\text{mL}$. How many milliliters will the nurse
draw up to deliver the dose?
A. 0.25 mL
B. 2 mL
C. 4 mL
D. 40 mL
Correct Answer: C
Rationale:
EASY
SOLVING PROBLEMS USING
DIMENSIONAL ANALYSIS
8TH EDITION
• AUTHOR(S)GLORIA PEARL
CRAIG
TEST BANK
,Question 1
Clinical Scenario: The healthcare provider prescribes
levothyroxine $125\text{ mcg}$ PO daily for a client with
hypothyroidism. The pharmacy supplies levothyroxine labeled
$0.125\text{ mg}$ per tablet. How many tablets will the nurse
administer?
A. 0.5 tablets
B. 1 tablet
C. 1.5 tablets
D. 2 tablets
Correct Answer: B
Rationale:
• Step 1 (Identify target): The goal is to find the number of
tablets to administer per dose ($\text{tablets/dose}$).
• Step 2 (Dimensional Analysis Setup): Convert the
prescribed micrograms ($\text{mcg}$) to milligrams
($\text{mg}$) to match the available unit, then solve for
tablets.
$$\frac{1\text{ tablet}}{0.125\text{ mg}} \times \frac{1\text{
mg}}{1,000\text{ mcg}} \times \frac{125\text{ mcg}}{1\text{
dose}}$$
, • Step 3 (Calculation & Solution):
$$\frac{125}{0.125 \times 1,000} = \frac{125}{125} = 1\text{
tablet per dose}$$
Medication Safety Note: Micrograms and milligrams are easily
confused. Always convert to a matching unit before dividing.
Levothyroxine is a narrow therapeutic index drug; a decimal
error can result in severe thyrotoxicosis or underdosing.
Question 2
Clinical Scenario: A provider orders potassium chloride liquid
$30\text{ mEq}$ PO twice daily for a client taking a loop
diuretic. The medication is supplied in a bottle labeled $20\text{
mEq}/15\text{ mL}$. How many milliliters should the nurse
administer per dose?
A. 10 mL
B. 15 mL
C. 22.5 mL
D. 30 mL
Correct Answer: C
Rationale:
• Step 1 (Identify target): Find the volume in milliliters
($\text{mL}$) required for the prescribed milliequivalents
($\text{mEq}$).
, • Step 2 (Dimensional Analysis Setup):
$$\frac{15\text{ mL}}{20\text{ mEq}} \times \frac{30\text{
mEq}}{1\text{ dose}}$$
• Step 3 (Calculation & Solution):
$$\frac{15 \times 30}{20} = \frac{450}{20} = 22.5\text{ mL}$$
Medication Safety Note: Liquid potassium chloride is highly
irritating to the gastrointestinal tract. The nurse should ensure
the client dilutes this volume in water or juice as directed to
prevent gastric mucosal injury.
Question 3
Clinical Scenario: The provider orders furosemide $40\text{
mg}$ intravenous push (IVP) stat for a client with acute
pulmonary edema. The vial on hand is labeled furosemide
$10\text{ mg}/\text{mL}$. How many milliliters will the nurse
draw up to deliver the dose?
A. 0.25 mL
B. 2 mL
C. 4 mL
D. 40 mL
Correct Answer: C
Rationale:
