NURS 251 Pharmacology Final Exam
Official Practice Exam Actual Exam
2026/2027 with Detailed Rationales |
Complete Exam-Style Questions | Pass
Guaranteed – A+ Graded
══════════════════════════════════════
SECTION 1: PHARMACOKINETICS & PHARMACODYNAMICS Q1 – Q10
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Question 1 of 50
A 68-year-old male with congestive heart failure is prescribed digoxin 0.25 mg PO daily. His
serum creatinine is 2.1 mg/dL, and his potassium level is 3.2 mEq/L. The nurse notes his
apical pulse is 52 bpm before the scheduled dose. Based on pharmacokinetic principles, what
is the nurse's priority action?
A. Administer the dose with a glass of orange juice to enhance absorption
B. Hold the dose and notify the provider immediately ✓ CORRECT
C. Crush the tablet and mix it with applesauce to improve bioavailability
D. Give the dose with a high-fat meal to increase protein binding
Correct Answer: B
Rationale: Digoxin has a narrow therapeutic index and is primarily excreted unchanged by the
kidneys; with a creatinine of 2.1 mg/dL indicating renal impairment and hypokalemia of 3.2
mEq/L increasing toxicity risk, a heart rate below 60 bpm is a critical sign of impending
digoxin toxicity that requires holding the dose. Option A is tempting because orange juice
contains potassium, but it does not address the immediate life-threatening bradycardia or the
drug's reduced clearance in renal failure. For Portage NURS 251, always check apical pulse
for a full minute before giving digoxin, and remember that hypokalemia potentiates digoxin
toxicity by displacing it from tissue binding sites.
Question 2 of 50
A 45-year-old female with a history of epilepsy is started on phenytoin 300 mg PO daily. The
nurse reviews her medication list and notes she also takes omeprazole 20 mg daily for GERD.
,The nurse understands that omeprazole may alter phenytoin levels through which
pharmacokinetic mechanism?
A. Omeprazole increases phenytoin absorption by raising gastric pH
B. Omeprazole inhibits hepatic CYP2C19 metabolism, increasing phenytoin levels ✓
CORRECT
C. Omeprazole induces hepatic glucuronidation, decreasing phenytoin half-life
D. Omeprazole competes with phenytoin for renal tubular secretion
Correct Answer: B
Rationale: Omeprazole is a potent inhibitor of the CYP2C19 enzyme, which is responsible for
metabolizing phenytoin in the liver; this inhibition decreases phenytoin clearance and can
lead to toxic accumulation. Option A is incorrect because raising gastric pH actually
decreases absorption of weakly acidic drugs like phenytoin, not increases it, and
omeprazole's primary interaction is metabolic rather than absorptive. On the NURS 251 exam,
always consider CYP450 interactions when combining anticonvulsants with proton pump
inhibitors or antifungals.
Question 3 of 50
A 55-year-old male with chronic liver disease secondary to alcohol use is prescribed
lorazepam 1 mg PO PRN for anxiety. The nurse recognizes that this benzodiazepine was
specifically chosen over diazepam because lorazepam undergoes which metabolic pathway?
A. Lorazepam is metabolized primarily by phase I oxidation in the liver
B. Lorazepam undergoes glucuronidation, which is preserved in liver disease ✓ CORRECT
C. Lorazepam is excreted unchanged by the kidneys without hepatic metabolism
D. Lorazepam is metabolized by CYP3A4, which is upregulated in cirrhosis
Correct Answer: B
Rationale: Lorazepam is conjugated directly to glucuronic acid via phase II glucuronidation, a
metabolic pathway that remains relatively functional even in advanced hepatic disease, unlike
the phase I oxidation required for diazepam metabolism. Option A is incorrect because
diazepam, not lorazepam, relies heavily on hepatic oxidation via CYP2C19 and CYP3A4, which
are significantly impaired in cirrhosis. For liver-compromised patients, prefer lorazepam,
oxazepam, or temazepam—the "LOT" drugs that use glucuronidation.
Question 4 of 50
A 32-year-old female with a urinary tract infection is prescribed ciprofloxacin 500 mg PO BID.
The nurse instructs the patient to avoid taking the medication with dairy products or
antacids. The nurse's teaching is based on which pharmacokinetic principle?
, A. Calcium and magnesium form insoluble chelation complexes that reduce absorption ✓
CORRECT
B. Dairy products increase gastric emptying, reducing drug contact time
C. Antacids alkalinize urine, preventing renal tubular reabsorption
D. Ciprofloxacin is a weak acid that requires an acidic environment for ionization
Correct Answer: A
Rationale: Fluoroquinolones like ciprofloxacin contain a carboxyl group that chelates divalent
and trivalent cations (Ca²⁺, Mg²⁺, Al³⁺, Fe²⁺) in the GI tract, forming insoluble complexes that
dramatically reduce oral bioavailability. Option B is incorrect because while gastric emptying
can affect absorption, the primary and clinically significant interaction with dairy and antacids
is chelation, not altered motility. Administer ciprofloxacin at least 2 hours before or 6 hours
after any product containing these cations.
Question 5 of 50
A 70-year-old male with atrial fibrillation is prescribed warfarin 5 mg PO daily with a target INR
of 2.0–3.0. His current INR is 1.4. The nurse understands that achieving the therapeutic effect
depends on which pharmacodynamic principle?
A. Warfarin directly inhibits platelet aggregation by blocking thromboxane A2 synthesis
B. Warfarin competitively antagonizes vitamin K at its receptor site, inhibiting synthesis of
clotting factors II, VII, IX, and X ✓ CORRECT
C. Warfarin enhances fibrinolysis by activating tissue plasminogen activator
D. Warfarin binds to antithrombin III, accelerating its inhibition of thrombin and factor Xa
Correct Answer: B
Rationale: Warfarin is a vitamin K epoxide reductase competitive antagonist that prevents the
gamma-carboxylation of clotting factors II, VII, IX, and X in the liver, thereby reducing their
functional activity and prolonging the INR. Option D describes the mechanism of heparin and
low molecular weight heparins, which is a common distractor on pharmacology exams
because both are anticoagulants but work through entirely different pathways. Remember:
warfarin affects synthesis (vitamin K dependent), while heparin enhances inhibition of
existing clotting factors.
Question 6 of 50
A 28-year-old female is receiving morphine 4 mg IV every 4 hours PRN for postoperative pain
following abdominal surgery. Four hours after her last dose, the nurse assesses her
respiratory rate at 8 breaths per minute with pinpoint pupils. The nurse prepares to administer
naloxone based on understanding of which pharmacodynamic concept?
A. Naloxone is a partial agonist that displaces morphine from mu-opioid receptors
Official Practice Exam Actual Exam
2026/2027 with Detailed Rationales |
Complete Exam-Style Questions | Pass
Guaranteed – A+ Graded
══════════════════════════════════════
SECTION 1: PHARMACOKINETICS & PHARMACODYNAMICS Q1 – Q10
══════════════════════════════════════
Question 1 of 50
A 68-year-old male with congestive heart failure is prescribed digoxin 0.25 mg PO daily. His
serum creatinine is 2.1 mg/dL, and his potassium level is 3.2 mEq/L. The nurse notes his
apical pulse is 52 bpm before the scheduled dose. Based on pharmacokinetic principles, what
is the nurse's priority action?
A. Administer the dose with a glass of orange juice to enhance absorption
B. Hold the dose and notify the provider immediately ✓ CORRECT
C. Crush the tablet and mix it with applesauce to improve bioavailability
D. Give the dose with a high-fat meal to increase protein binding
Correct Answer: B
Rationale: Digoxin has a narrow therapeutic index and is primarily excreted unchanged by the
kidneys; with a creatinine of 2.1 mg/dL indicating renal impairment and hypokalemia of 3.2
mEq/L increasing toxicity risk, a heart rate below 60 bpm is a critical sign of impending
digoxin toxicity that requires holding the dose. Option A is tempting because orange juice
contains potassium, but it does not address the immediate life-threatening bradycardia or the
drug's reduced clearance in renal failure. For Portage NURS 251, always check apical pulse
for a full minute before giving digoxin, and remember that hypokalemia potentiates digoxin
toxicity by displacing it from tissue binding sites.
Question 2 of 50
A 45-year-old female with a history of epilepsy is started on phenytoin 300 mg PO daily. The
nurse reviews her medication list and notes she also takes omeprazole 20 mg daily for GERD.
,The nurse understands that omeprazole may alter phenytoin levels through which
pharmacokinetic mechanism?
A. Omeprazole increases phenytoin absorption by raising gastric pH
B. Omeprazole inhibits hepatic CYP2C19 metabolism, increasing phenytoin levels ✓
CORRECT
C. Omeprazole induces hepatic glucuronidation, decreasing phenytoin half-life
D. Omeprazole competes with phenytoin for renal tubular secretion
Correct Answer: B
Rationale: Omeprazole is a potent inhibitor of the CYP2C19 enzyme, which is responsible for
metabolizing phenytoin in the liver; this inhibition decreases phenytoin clearance and can
lead to toxic accumulation. Option A is incorrect because raising gastric pH actually
decreases absorption of weakly acidic drugs like phenytoin, not increases it, and
omeprazole's primary interaction is metabolic rather than absorptive. On the NURS 251 exam,
always consider CYP450 interactions when combining anticonvulsants with proton pump
inhibitors or antifungals.
Question 3 of 50
A 55-year-old male with chronic liver disease secondary to alcohol use is prescribed
lorazepam 1 mg PO PRN for anxiety. The nurse recognizes that this benzodiazepine was
specifically chosen over diazepam because lorazepam undergoes which metabolic pathway?
A. Lorazepam is metabolized primarily by phase I oxidation in the liver
B. Lorazepam undergoes glucuronidation, which is preserved in liver disease ✓ CORRECT
C. Lorazepam is excreted unchanged by the kidneys without hepatic metabolism
D. Lorazepam is metabolized by CYP3A4, which is upregulated in cirrhosis
Correct Answer: B
Rationale: Lorazepam is conjugated directly to glucuronic acid via phase II glucuronidation, a
metabolic pathway that remains relatively functional even in advanced hepatic disease, unlike
the phase I oxidation required for diazepam metabolism. Option A is incorrect because
diazepam, not lorazepam, relies heavily on hepatic oxidation via CYP2C19 and CYP3A4, which
are significantly impaired in cirrhosis. For liver-compromised patients, prefer lorazepam,
oxazepam, or temazepam—the "LOT" drugs that use glucuronidation.
Question 4 of 50
A 32-year-old female with a urinary tract infection is prescribed ciprofloxacin 500 mg PO BID.
The nurse instructs the patient to avoid taking the medication with dairy products or
antacids. The nurse's teaching is based on which pharmacokinetic principle?
, A. Calcium and magnesium form insoluble chelation complexes that reduce absorption ✓
CORRECT
B. Dairy products increase gastric emptying, reducing drug contact time
C. Antacids alkalinize urine, preventing renal tubular reabsorption
D. Ciprofloxacin is a weak acid that requires an acidic environment for ionization
Correct Answer: A
Rationale: Fluoroquinolones like ciprofloxacin contain a carboxyl group that chelates divalent
and trivalent cations (Ca²⁺, Mg²⁺, Al³⁺, Fe²⁺) in the GI tract, forming insoluble complexes that
dramatically reduce oral bioavailability. Option B is incorrect because while gastric emptying
can affect absorption, the primary and clinically significant interaction with dairy and antacids
is chelation, not altered motility. Administer ciprofloxacin at least 2 hours before or 6 hours
after any product containing these cations.
Question 5 of 50
A 70-year-old male with atrial fibrillation is prescribed warfarin 5 mg PO daily with a target INR
of 2.0–3.0. His current INR is 1.4. The nurse understands that achieving the therapeutic effect
depends on which pharmacodynamic principle?
A. Warfarin directly inhibits platelet aggregation by blocking thromboxane A2 synthesis
B. Warfarin competitively antagonizes vitamin K at its receptor site, inhibiting synthesis of
clotting factors II, VII, IX, and X ✓ CORRECT
C. Warfarin enhances fibrinolysis by activating tissue plasminogen activator
D. Warfarin binds to antithrombin III, accelerating its inhibition of thrombin and factor Xa
Correct Answer: B
Rationale: Warfarin is a vitamin K epoxide reductase competitive antagonist that prevents the
gamma-carboxylation of clotting factors II, VII, IX, and X in the liver, thereby reducing their
functional activity and prolonging the INR. Option D describes the mechanism of heparin and
low molecular weight heparins, which is a common distractor on pharmacology exams
because both are anticoagulants but work through entirely different pathways. Remember:
warfarin affects synthesis (vitamin K dependent), while heparin enhances inhibition of
existing clotting factors.
Question 6 of 50
A 28-year-old female is receiving morphine 4 mg IV every 4 hours PRN for postoperative pain
following abdominal surgery. Four hours after her last dose, the nurse assesses her
respiratory rate at 8 breaths per minute with pinpoint pupils. The nurse prepares to administer
naloxone based on understanding of which pharmacodynamic concept?
A. Naloxone is a partial agonist that displaces morphine from mu-opioid receptors
