Drug Dosage Calculations Practice Exam
(Quiz 25 Questions and Correct Answers)
with Rationales
1. 1. Question
A home health nurse is caring for a 72-year-old patient with a history of
gastroesophageal reflux disease (GERD). The patient has been prescribed
magnesium hydroxide/aluminum hydroxide (Maalox) 30 mL PO to alleviate
symptoms. However, the patient does not have any calibrated medication
measuring devices at home. The nurse must instruct the patient on how to
measure the dose using ordinary household measuring devices accurately. How
will you instruct the patient to measure the dose using ordinary household
measuring devices?
Fill in the blanks. Record your answer to the nearest whole number.
Answer: BLANK 1 of 1 tbsp.
Answer: Fill in the blank 1 of 1 (2) tbsp.
Correct answer:
2 tbsp.
Computation
30mL×1tbsp15mL=2tbsp30mL×15mL1tbsp=2tbsp
, One tablespoon is equal to 15 mL.
Convert 30 mL to tablespoons by multiplying it by one tablespoon.
Then, divide 30 by 15 mL to get the final answer of 2 tbsp.
2. 2. Question
A 66-year-old patient with a history of deep vein thrombosis (DVT) is currently on
warfarin (Coumadin) therapy. The patient has a bottle of Warfarin (Coumadin) 5
mg tablets at home. After reviewing the patient’s most recent international
normalized ratio (INR) results, the healthcare provider calls the patient and
instructs them to adjust their daily dosage to 7.5 mg/day. The patient is unsure
about how to adjust their tablet intake to achieve the new dosage. As a nurse,
you are asked to guide the patient on the correct number of tablets they should
take. Considering the patient has scored tablets, how many tablets should the
patient take daily?
Fill in the blank and record your answer using one decimal place.
Answer: BLANK 1 of 1 tablet(s)
Answer: Fill in the blank 1 of 1 (1.5) tablet(s)
Correct answer
1.5 tablet
Formula
Desired(D)×Vehicle(V)On Hand(H)=amount to administerOn Hand(H)Desi
red(D)×Vehicle(V)=amount to administer
Computation
, 7.5mg×1tablet5mg=1.5tablets7.5mg×5mg1tablet=1.5tablets
Use the standard formula above.
First, multiply the desired dose (7.5 mg) to the vehicle (1 tablet) to get 7.5mg.
Then, divide 7.5 mg by the drug on hand (5 mg) to get 1.5 tablets.
3. 3. Question
A 60-year-old male patient is admitted to the hospital with a diagnosis of peptic
ulcer disease (PUD). The healthcare provider orders an intravenous piggyback
(IVPB) of ranitidine (Zantac) 50 mg in 50 mL D5W to be administered over 30
minutes. The primary nurse notices that the IV tubing has a drip factor of 15. The
nurse is responsible for setting the IV infusion controller to regulate the flow of
medication. How many drops per minute should the nurse set on the IV infusion
controller to administer the IVPB correctly?
Fill in the blanks and round your final answer to a whole number.
Answer: BLANK 1 of 1 gtts/minute
Answer: Fill in the blank 1 of 1 (25) gtts/minute
Correct answer
25 gtts/minute
Formula
Drops per minute (gtts/min)= Total infusion volume ×drop factortotal
time of infusion in minutesDrops per minute (gtts/min)= total time of infusion i
n minutesTotal infusion volume ×drop factor
, Computation
50mL30mins×15gttsmL=25gtts/minute30mins50mL×mL15gtts=25gtts/minute
Use the IV flow rate formula for gtts/minute above.
Multiply 50 mL (total volume) to 15 gtts (drop factor) to get 750 gtts.
Divide 750 gtts with 30 minutes (time in minutes) to get 25 gtts/minute.
4. 4. Question
A 45-year-old female patient with a history of anxiety disorder is prescribed
alprazolam (Xanax) 0.5 mg orally. However, the pharmacy mistakenly dispensed
Xanax 0.25 mg tablets. The nurse must administer the correct dose of 0.5 mg.
How many tablets of Xanax 0.25 mg should the nurse give to the patient?
Fill in the blanks and round your answer to the nearest whole number.
Answer: BLANK 1 of 1 tablets(s)
Answer: Fill in the blank 1 of 1 (2) tablets(s)
Correct answer
2 tablets
Formula
(Quiz 25 Questions and Correct Answers)
with Rationales
1. 1. Question
A home health nurse is caring for a 72-year-old patient with a history of
gastroesophageal reflux disease (GERD). The patient has been prescribed
magnesium hydroxide/aluminum hydroxide (Maalox) 30 mL PO to alleviate
symptoms. However, the patient does not have any calibrated medication
measuring devices at home. The nurse must instruct the patient on how to
measure the dose using ordinary household measuring devices accurately. How
will you instruct the patient to measure the dose using ordinary household
measuring devices?
Fill in the blanks. Record your answer to the nearest whole number.
Answer: BLANK 1 of 1 tbsp.
Answer: Fill in the blank 1 of 1 (2) tbsp.
Correct answer:
2 tbsp.
Computation
30mL×1tbsp15mL=2tbsp30mL×15mL1tbsp=2tbsp
, One tablespoon is equal to 15 mL.
Convert 30 mL to tablespoons by multiplying it by one tablespoon.
Then, divide 30 by 15 mL to get the final answer of 2 tbsp.
2. 2. Question
A 66-year-old patient with a history of deep vein thrombosis (DVT) is currently on
warfarin (Coumadin) therapy. The patient has a bottle of Warfarin (Coumadin) 5
mg tablets at home. After reviewing the patient’s most recent international
normalized ratio (INR) results, the healthcare provider calls the patient and
instructs them to adjust their daily dosage to 7.5 mg/day. The patient is unsure
about how to adjust their tablet intake to achieve the new dosage. As a nurse,
you are asked to guide the patient on the correct number of tablets they should
take. Considering the patient has scored tablets, how many tablets should the
patient take daily?
Fill in the blank and record your answer using one decimal place.
Answer: BLANK 1 of 1 tablet(s)
Answer: Fill in the blank 1 of 1 (1.5) tablet(s)
Correct answer
1.5 tablet
Formula
Desired(D)×Vehicle(V)On Hand(H)=amount to administerOn Hand(H)Desi
red(D)×Vehicle(V)=amount to administer
Computation
, 7.5mg×1tablet5mg=1.5tablets7.5mg×5mg1tablet=1.5tablets
Use the standard formula above.
First, multiply the desired dose (7.5 mg) to the vehicle (1 tablet) to get 7.5mg.
Then, divide 7.5 mg by the drug on hand (5 mg) to get 1.5 tablets.
3. 3. Question
A 60-year-old male patient is admitted to the hospital with a diagnosis of peptic
ulcer disease (PUD). The healthcare provider orders an intravenous piggyback
(IVPB) of ranitidine (Zantac) 50 mg in 50 mL D5W to be administered over 30
minutes. The primary nurse notices that the IV tubing has a drip factor of 15. The
nurse is responsible for setting the IV infusion controller to regulate the flow of
medication. How many drops per minute should the nurse set on the IV infusion
controller to administer the IVPB correctly?
Fill in the blanks and round your final answer to a whole number.
Answer: BLANK 1 of 1 gtts/minute
Answer: Fill in the blank 1 of 1 (25) gtts/minute
Correct answer
25 gtts/minute
Formula
Drops per minute (gtts/min)= Total infusion volume ×drop factortotal
time of infusion in minutesDrops per minute (gtts/min)= total time of infusion i
n minutesTotal infusion volume ×drop factor
, Computation
50mL30mins×15gttsmL=25gtts/minute30mins50mL×mL15gtts=25gtts/minute
Use the IV flow rate formula for gtts/minute above.
Multiply 50 mL (total volume) to 15 gtts (drop factor) to get 750 gtts.
Divide 750 gtts with 30 minutes (time in minutes) to get 25 gtts/minute.
4. 4. Question
A 45-year-old female patient with a history of anxiety disorder is prescribed
alprazolam (Xanax) 0.5 mg orally. However, the pharmacy mistakenly dispensed
Xanax 0.25 mg tablets. The nurse must administer the correct dose of 0.5 mg.
How many tablets of Xanax 0.25 mg should the nurse give to the patient?
Fill in the blanks and round your answer to the nearest whole number.
Answer: BLANK 1 of 1 tablets(s)
Answer: Fill in the blank 1 of 1 (2) tablets(s)
Correct answer
2 tablets
Formula
