NURS 251 Pharmacology Complete Study Guide for
Nursing Students, Drug Classifications, Mechanisms of
Action, NCLEX-Style Pharmacology Questions and
Answers, Medication Safety Concepts, Dosage Calculations,
and High-Yield Exam Review for Guaranteed Nursing
Exam Success
Question 1: A nurse is preparing to administer a medication that is highly protein-bound. Which
patient condition would most likely increase the risk of drug toxicity?
A. Dehydration
B. Hypoalbuminemia
C. Hypertension
D. Hyperglycemia
CORRECT ANSWER: B. Hypoalbuminemia
Rationale: Medications that are highly protein-bound attach to plasma proteins, primarily
albumin. In hypoalbuminemia, fewer binding sites are available, resulting in increased free
(active) drug concentration in the bloodstream, which elevates the risk of toxicity even at
standard doses.
Question 2: Which route of medication administration provides the most rapid onset of action?
A. Oral
B. Subcutaneous
C. Intravenous
D. Transdermal
CORRECT ANSWER: C. Intravenous
Rationale: Intravenous administration delivers medication directly into the systemic circulation,
bypassing absorption barriers. This results in immediate bioavailability and the fastest onset of
action compared to other routes.
Question 3: A patient receiving warfarin asks why they must avoid cranberry juice. The nurse's
best response is based on which pharmacological principle?
A. Cranberry juice increases warfarin metabolism
B. Cranberry juice decreases warfarin absorption
C. Cranberry juice potentiates warfarin's anticoagulant effect
D. Cranberry juice causes warfarin to precipitate in the kidneys
,CORRECT ANSWER: C. Cranberry juice potentiates warfarin's anticoagulant effect
Rationale: Cranberry juice may inhibit cytochrome P450 enzymes and enhance warfarin's
anticoagulant effect, increasing the risk of bleeding. Patients on warfarin should be advised to
avoid significant consumption of cranberry products.
Question 4: Which assessment finding in a patient receiving digoxin requires immediate nursing
intervention?
A. Heart rate of 72 beats per minute
B. Serum potassium level of 4.0 mEq/L
C. Visual disturbances described as yellow-green halos
D. Blood pressure of 128/84 mmHg
CORRECT ANSWER: C. Visual disturbances described as yellow-green halos
Rationale: Visual disturbances such as yellow-green halos are classic signs of digoxin toxicity.
This requires immediate assessment, holding the dose, and notifying the provider, as toxicity
can lead to life-threatening dysrhythmias.
Question 5: A nurse is teaching a patient about sublingual nitroglycerin for angina. Which
statement by the patient indicates understanding?
A. "I should swallow the tablet with water for faster relief."
B. "I will store the tablets in the original dark glass bottle."
C. "I can take up to five tablets if chest pain persists."
D. "I should expect a mild headache, so I will avoid taking it."
CORRECT ANSWER: B. "I will store the tablets in the original dark glass bottle."
Rationale: Nitroglycerin is light- and air-sensitive; storing it in the original dark glass bottle
preserves potency. Sublingual tablets should not be swallowed, no more than three doses
should be taken for acute angina, and headache is a common, expected side effect that does
not preclude use.
Question 6: Which medication classification is most appropriate for a patient experiencing an
acute asthma exacerbation?
A. Long-acting beta-2 agonists
B. Inhaled corticosteroids
C. Short-acting beta-2 agonists
,D. Leukotriene modifiers
CORRECT ANSWER: C. Short-acting beta-2 agonists
Rationale: Short-acting beta-2 agonists (e.g., albuterol) provide rapid bronchodilation and are
first-line for acute asthma symptoms. Long-acting agents and corticosteroids are for
maintenance, not rescue.
Question 7: A patient is prescribed metformin for type 2 diabetes. Which instruction should the
nurse prioritize?
A. Take with a full glass of milk to prevent nausea
B. Discontinue if experiencing mild diarrhea
C. Avoid alcohol consumption while taking this medication
D. Take on an empty stomach for maximum absorption
CORRECT ANSWER: C. Avoid alcohol consumption while taking this medication
Rationale: Alcohol increases the risk of lactic acidosis, a rare but serious complication of
metformin. Patients should be instructed to limit or avoid alcohol. Metformin is typically taken
with food to reduce GI upset, and mild diarrhea often resolves with continued use.
Question 8: Which laboratory value should a nurse monitor most closely in a patient receiving
vancomycin?
A. Serum creatinine
B. Liver enzymes
C. Thyroid-stimulating hormone
D. Complete blood count with differential
CORRECT ANSWER: A. Serum creatinine
Rationale: Vancomycin is nephrotoxic; serum creatinine and estimated glomerular filtration
rate should be monitored regularly to assess kidney function and adjust dosing to prevent acute
kidney injury.
Question 9: A patient receiving morphine via patient-controlled analgesia (PCA) has a
respiratory rate of 8 breaths per minute and is difficult to arouse. Which medication should the
nurse anticipate administering?
A. Flumazenil
B. Naloxone
, C. Acetylcysteine
D. Protamine sulfate
CORRECT ANSWER: B. Naloxone
Rationale: Naloxone is an opioid antagonist that rapidly reverses opioid-induced respiratory
depression and sedation. Flumazenil reverses benzodiazepines; acetylcysteine treats
acetaminophen toxicity; protamine reverses heparin.
Question 10: Which statement by a patient starting lisinopril indicates the need for further
teaching?
A. "I will rise slowly from sitting to prevent dizziness."
B. "I should report a persistent dry cough to my provider."
C. "I will use salt substitutes to enhance the medication's effect."
D. "I need regular blood tests to monitor my kidney function."
CORRECT ANSWER: C. "I will use salt substitutes to enhance the medication's effect."
Rationale: Many salt substitutes contain potassium, and ACE inhibitors like lisinopril can cause
hyperkalemia. Patients should avoid potassium-containing salt substitutes unless approved by
their provider.
Question 11: A nurse is preparing to administer insulin glargine. Which action is essential?
A. Shake the vial vigorously before drawing up the dose
B. Mix with regular insulin in the same syringe
C. Administer at the same time each day
D. Give only when blood glucose exceeds 200 mg/dL
CORRECT ANSWER: C. Administer at the same time each day
Rationale: Insulin glargine is a long-acting basal insulin with a relatively flat, 24-hour duration.
Consistent daily administration time maintains stable blood glucose levels. It should not be
shaken, mixed with other insulins, or used as a sliding-scale medication.
Question 12: Which adverse effect is most characteristic of first-generation antihistamines like
diphenhydramine?
A. Hypertension
B. Sedation
C. Diarrhea
Nursing Students, Drug Classifications, Mechanisms of
Action, NCLEX-Style Pharmacology Questions and
Answers, Medication Safety Concepts, Dosage Calculations,
and High-Yield Exam Review for Guaranteed Nursing
Exam Success
Question 1: A nurse is preparing to administer a medication that is highly protein-bound. Which
patient condition would most likely increase the risk of drug toxicity?
A. Dehydration
B. Hypoalbuminemia
C. Hypertension
D. Hyperglycemia
CORRECT ANSWER: B. Hypoalbuminemia
Rationale: Medications that are highly protein-bound attach to plasma proteins, primarily
albumin. In hypoalbuminemia, fewer binding sites are available, resulting in increased free
(active) drug concentration in the bloodstream, which elevates the risk of toxicity even at
standard doses.
Question 2: Which route of medication administration provides the most rapid onset of action?
A. Oral
B. Subcutaneous
C. Intravenous
D. Transdermal
CORRECT ANSWER: C. Intravenous
Rationale: Intravenous administration delivers medication directly into the systemic circulation,
bypassing absorption barriers. This results in immediate bioavailability and the fastest onset of
action compared to other routes.
Question 3: A patient receiving warfarin asks why they must avoid cranberry juice. The nurse's
best response is based on which pharmacological principle?
A. Cranberry juice increases warfarin metabolism
B. Cranberry juice decreases warfarin absorption
C. Cranberry juice potentiates warfarin's anticoagulant effect
D. Cranberry juice causes warfarin to precipitate in the kidneys
,CORRECT ANSWER: C. Cranberry juice potentiates warfarin's anticoagulant effect
Rationale: Cranberry juice may inhibit cytochrome P450 enzymes and enhance warfarin's
anticoagulant effect, increasing the risk of bleeding. Patients on warfarin should be advised to
avoid significant consumption of cranberry products.
Question 4: Which assessment finding in a patient receiving digoxin requires immediate nursing
intervention?
A. Heart rate of 72 beats per minute
B. Serum potassium level of 4.0 mEq/L
C. Visual disturbances described as yellow-green halos
D. Blood pressure of 128/84 mmHg
CORRECT ANSWER: C. Visual disturbances described as yellow-green halos
Rationale: Visual disturbances such as yellow-green halos are classic signs of digoxin toxicity.
This requires immediate assessment, holding the dose, and notifying the provider, as toxicity
can lead to life-threatening dysrhythmias.
Question 5: A nurse is teaching a patient about sublingual nitroglycerin for angina. Which
statement by the patient indicates understanding?
A. "I should swallow the tablet with water for faster relief."
B. "I will store the tablets in the original dark glass bottle."
C. "I can take up to five tablets if chest pain persists."
D. "I should expect a mild headache, so I will avoid taking it."
CORRECT ANSWER: B. "I will store the tablets in the original dark glass bottle."
Rationale: Nitroglycerin is light- and air-sensitive; storing it in the original dark glass bottle
preserves potency. Sublingual tablets should not be swallowed, no more than three doses
should be taken for acute angina, and headache is a common, expected side effect that does
not preclude use.
Question 6: Which medication classification is most appropriate for a patient experiencing an
acute asthma exacerbation?
A. Long-acting beta-2 agonists
B. Inhaled corticosteroids
C. Short-acting beta-2 agonists
,D. Leukotriene modifiers
CORRECT ANSWER: C. Short-acting beta-2 agonists
Rationale: Short-acting beta-2 agonists (e.g., albuterol) provide rapid bronchodilation and are
first-line for acute asthma symptoms. Long-acting agents and corticosteroids are for
maintenance, not rescue.
Question 7: A patient is prescribed metformin for type 2 diabetes. Which instruction should the
nurse prioritize?
A. Take with a full glass of milk to prevent nausea
B. Discontinue if experiencing mild diarrhea
C. Avoid alcohol consumption while taking this medication
D. Take on an empty stomach for maximum absorption
CORRECT ANSWER: C. Avoid alcohol consumption while taking this medication
Rationale: Alcohol increases the risk of lactic acidosis, a rare but serious complication of
metformin. Patients should be instructed to limit or avoid alcohol. Metformin is typically taken
with food to reduce GI upset, and mild diarrhea often resolves with continued use.
Question 8: Which laboratory value should a nurse monitor most closely in a patient receiving
vancomycin?
A. Serum creatinine
B. Liver enzymes
C. Thyroid-stimulating hormone
D. Complete blood count with differential
CORRECT ANSWER: A. Serum creatinine
Rationale: Vancomycin is nephrotoxic; serum creatinine and estimated glomerular filtration
rate should be monitored regularly to assess kidney function and adjust dosing to prevent acute
kidney injury.
Question 9: A patient receiving morphine via patient-controlled analgesia (PCA) has a
respiratory rate of 8 breaths per minute and is difficult to arouse. Which medication should the
nurse anticipate administering?
A. Flumazenil
B. Naloxone
, C. Acetylcysteine
D. Protamine sulfate
CORRECT ANSWER: B. Naloxone
Rationale: Naloxone is an opioid antagonist that rapidly reverses opioid-induced respiratory
depression and sedation. Flumazenil reverses benzodiazepines; acetylcysteine treats
acetaminophen toxicity; protamine reverses heparin.
Question 10: Which statement by a patient starting lisinopril indicates the need for further
teaching?
A. "I will rise slowly from sitting to prevent dizziness."
B. "I should report a persistent dry cough to my provider."
C. "I will use salt substitutes to enhance the medication's effect."
D. "I need regular blood tests to monitor my kidney function."
CORRECT ANSWER: C. "I will use salt substitutes to enhance the medication's effect."
Rationale: Many salt substitutes contain potassium, and ACE inhibitors like lisinopril can cause
hyperkalemia. Patients should avoid potassium-containing salt substitutes unless approved by
their provider.
Question 11: A nurse is preparing to administer insulin glargine. Which action is essential?
A. Shake the vial vigorously before drawing up the dose
B. Mix with regular insulin in the same syringe
C. Administer at the same time each day
D. Give only when blood glucose exceeds 200 mg/dL
CORRECT ANSWER: C. Administer at the same time each day
Rationale: Insulin glargine is a long-acting basal insulin with a relatively flat, 24-hour duration.
Consistent daily administration time maintains stable blood glucose levels. It should not be
shaken, mixed with other insulins, or used as a sliding-scale medication.
Question 12: Which adverse effect is most characteristic of first-generation antihistamines like
diphenhydramine?
A. Hypertension
B. Sedation
C. Diarrhea
