NURS 6521 Advanced Pharmacology
Final Exam - Version C
Week 11 | Walden University
2026-2027 Academic Year
Total Questions: 100 Format: Multiple Choice (A-D)
Cognitive Levels: 25% Recall, 55% Application, Question Style: 75% Scenario-based, 20% Direct
20% Analysis Recall, 5% Clinical Reasoning
Sections: 8 comprehensive sections Aligned With: Walden NURS 6521 Curriculum &
APRN Competencies
Instructions: Select the single best answer for each question. Each question has exactly one correct response. The
correct answer is marked with [CORRECT] and followed by a detailed rationale explaining the pharmacotherapeutic
reasoning, mechanism of action, adverse effects, drug interactions, and clinical indications aligned with Walden
University NURS 6521 Advanced Pharmacology curriculum and APRN competencies.
Section 1: Pharmacokinetics and Pharmacodynamics (ADME, Drug
Interactions, Half-Life, Therapeutic Index, & Special Populations)
(Q1-Q20)
Q1: A 72-year-old female patient with chronic kidney disease (eGFR 28 mL/min) is prescribed a
medication that is 90% renally excreted. Which pharmacokinetic principle best explains why dose
adjustment is necessary in this patient?
A. The volume of distribution (Vd) is increased due to decreased plasma protein binding.
B. The elimination half-life (t½) will be prolonged, leading to drug accumulation and potential
toxicity. [CORRECT]
C. First-pass metabolism is enhanced, requiring a higher loading dose.
D. Hepatic CYP450 enzyme activity is upregulated, accelerating drug clearance.
Correct Answer: B
Rationale: Renal excretion is the primary elimination route for many drugs. In renal impairment (eGFR <30),
glomerular filtration and tubular secretion are reduced, which prolongs the elimination half-life (t½) and increases
the risk of drug accumulation and toxicity. Dose reduction or interval extension is mandatory. Choice A describes
distribution changes, not elimination. Choice C is incorrect because first-pass metabolism occurs in the liver, not the
kidney. Choice D is incorrect because hepatic metabolism is independent of renal function in this context.
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,NURS 6521 Advanced Pharmacology Final Exam - Version C Walden University | 2026-2027
Q2: A patient taking warfarin 5 mg daily for atrial fibrillation is newly prescribed rifampin for
tuberculosis. The nurse practitioner anticipates which effect on the international normalized ratio
(INR)?
A. INR will increase due to CYP450 inhibition by rifampin, increasing bleeding risk.
B. INR will decrease due to CYP450 induction by rifampin, requiring a warfarin dose increase.
[CORRECT]
C. INR will remain unchanged because rifampin does not affect warfarin metabolism.
D. INR will fluctuate unpredictably due to displacement from plasma proteins.
Correct Answer: B
Rationale: Rifampin is a potent CYP450 inducer, particularly CYP3A4 and CYP2C9. Warfarin is metabolized by
CYP2C9 (S-isomer) and CYP1A2/CYP3A4 (R-isomer). Induction accelerates warfarin metabolism, lowering plasma
levels and decreasing the INR, which raises thrombotic risk. The warfarin dose must typically be increased 2- to
5-fold. Choice A reverses the effect. Choice C is incorrect—rifampin is a classic inducer. Choice D describes a
distribution interaction, not the metabolic effect that predominates here.
Q3: A neonate receiving a water-soluble medication has a significantly larger volume of distribution
(Vd) for that drug compared with an adult. Which physiological characteristic of neonates best
explains this finding?
A. Decreased total body water and increased fat composition.
B. Immature blood-brain barrier allowing greater CNS penetration.
C. Higher percentage of total body water and extracellular fluid. [CORRECT]
D. Enhanced hepatic conjugation resulting in slower elimination.
Correct Answer: C
Rationale: Neonates have approximately 75-80% total body water (vs. 60% in adults) and a much larger
extracellular fluid compartment. Water-soluble (hydrophilic) drugs distribute into this expanded aqueous volume,
producing a larger Vd and requiring weight-based dosing adjustments. Choice A is incorrect—neonates have less fat,
not more. Choice B describes distribution to the CNS, not total Vd. Choice D describes metabolism, not distribution.
Q4: A patient asks why their provider recommends taking levothyroxine on an empty stomach 30-60
minutes before breakfast. Which pharmacokinetic concept is the primary reason?
A. First-pass metabolism is reduced when taken without food.
B. Food, especially calcium and iron, impairs absorption by chelation. [CORRECT]
C. Levothyroxine undergoes enterohepatic recirculation that food disrupts.
D. Taking it with food increases Vd and reduces therapeutic effect.
Correct Answer: B
Rationale: Levothyroxine absorption occurs in the small intestine and is significantly impaired by food, particularly
calcium, iron, antacids, and fiber, which chelate or bind the drug. Taking it on an empty stomach ensures consistent,
maximal absorption and stable TSH levels. Choice A is incorrect—levothyroxine is not significantly first-pass
metabolized. Choice C is incorrect—levothyroxine does not undergo significant enterohepatic recirculation. Choice D
is a distribution issue, not the absorption concern that drives administration instructions.
Q5: A drug with a half-life of 12 hours is administered as a maintenance dose once daily.
Approximately how long will it take to reach steady-state plasma concentration?
A. 12 hours (1 half-life).
B. 24 hours (2 half-lives).
C. 48-60 hours (4-5 half-lives). [CORRECT]
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D. 7 days, regardless of half-life.
Correct Answer: C
Rationale: Steady state is achieved when the rate of drug administration equals the rate of elimination, which takes
approximately 4-5 half-lives. For a drug with t½ = 12 hours, steady state is reached in 48-60 hours. This principle
guides clinical decisions about when to assess therapeutic effect or measure drug levels. Choice A and B are too short.
Choice D ignores the relationship between half-life and steady state. If a rapid effect is needed, a loading dose can
be given to achieve therapeutic levels quickly.
Q6: Which of the following patients is at highest risk for developing digoxin toxicity? A patient
who:
A. Has serum potassium of 4.2 mEq/L and takes digoxin 0.125 mg daily.
B. Is concurrently taking furosemide 40 mg daily and has a potassium of 2.9 mEq/L. [CORRECT]
C. Takes digoxin with food and has normal renal function.
D. Has serum digoxin level of 1.0 ng/mL with normal renal and electrolyte status.
Correct Answer: B
Rationale: Digoxin has a narrow therapeutic index (0.8-2.0 ng/mL), and hypokalemia dramatically increases the
risk of toxicity because potassium and digoxin compete for the same binding site on the Na+/K+-ATPase pump.
When potassium is low, more digoxin binds, causing toxicity even at therapeutic serum levels. Loop diuretics like
furosemide cause hypokalemia. Choice A is safe (normal K+). Choice C does not increase toxicity risk. Choice D
represents a therapeutic level with no risk factors.
Q7: A 68-year-old patient is prescribed fluoxetine 20 mg daily for depression. Three days later, the
patient reports no improvement in mood. What is the most appropriate response based on
pharmacokinetic principles?
A. Increase the dose immediately to 40 mg daily for faster effect.
B. Discontinue fluoxetine and switch to a different antidepressant.
C. Educate the patient that therapeutic effects typically take 4-6 weeks to manifest. [CORRECT]
D. Add a second antidepressant to augment the effect.
Correct Answer: C
Rationale: Although fluoxetine reaches steady-state plasma levels within ~4-5 half-lives (about 4 weeks given its long
half-life of 1-4 days, and norfluoxetine 7-15 days), the therapeutic antidepressant effect typically requires 4-6
weeks due to downstream neuroadaptive changes (receptor downregulation, neurogenesis). Premature dose escalation
increases side effect risk without benefit. Choice A is premature. Choice B is inappropriate before adequate trial.
Choice D risks serotonin syndrome and is contraindicated.
Q8: Grapefruit juice is known to interact with multiple medications. What is the primary
mechanism by which grapefruit juice increases drug levels?
A. Induction of CYP3A4 in the liver, accelerating metabolism.
B. Inhibition of CYP3A4 in the intestinal wall, reducing first-pass metabolism. [CORRECT]
C. Displacement of drugs from plasma protein binding sites.
D. Enhancement of renal tubular secretion competition.
Correct Answer: B
Rationale: Grapefruit juice irreversibly inhibits CYP3A4 enzymes in the intestinal wall (not the liver), reducing
pre-systemic first-pass metabolism and increasing bioavailability of CYP3A4 substrates such as statins (simvastatin,
atorvastatin), calcium channel blockers, and cyclosporine. The effect can last 24-72 hours. Choice A is the opposite
effect. Choice C describes a protein-binding interaction. Choice D describes a renal interaction. The clinical impact
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, NURS 6521 Advanced Pharmacology Final Exam - Version C Walden University | 2026-2027
can be significant—simvastatin levels may increase 3-fold, raising rhabdomyolysis risk.
Q9: St. John's Wort is self-prescribed by a patient taking oral contraceptive pills (OCPs). What is
the most likely clinical consequence?
A. Increased OCP effectiveness due to additive estrogen effects.
B. Decreased OCP effectiveness and potential unintended pregnancy due to CYP3A4 induction.
[CORRECT]
C. No change in OCP effectiveness; St. John's Wort is safe in combination.
D. Increased risk of thromboembolism due to additive progestogenic effects.
Correct Answer: B
Rationale: St. John's Wort is a potent inducer of CYP3A4 and P-glycoprotein, which accelerates metabolism of
estrogen and progestin components of OCPs, lowering their plasma concentrations and reducing contraceptive
efficacy. Unintended pregnancies have been documented. Choice A is incorrect—St. John's Wort does not add
estrogen. Choice C is a dangerous misconception. Choice D describes a thrombotic risk, not the metabolic effect.
Patients should be counseled to avoid this combination or use backup contraception.
Q10: According to the Beers Criteria, which of the following medications is potentially
inappropriate for use in a 78-year-old patient with a history of falls and cognitive impairment?
A. Lisinopril 10 mg daily for hypertension.
B. Diphenhydramine 50 mg at bedtime for insomnia. [CORRECT]
C. Acetaminophen 650 mg every 6 hours for osteoarthritis.
D. Metformin 500 mg twice daily for type 2 diabetes.
Correct Answer: B
Rationale: Diphenhydramine is a strong anticholinergic (blocks muscarinic receptors) and is on the Beers Criteria list
of potentially inappropriate medications in older adults due to risks of confusion, dry mouth, constipation, urinary
retention, blurred vision, and falls. Safer alternatives for insomnia include non-pharmacological measures or
low-dose melatonin. Choice A, C, and D are appropriate in older adults when indicated. The Beers Criteria serves as
a guide to reduce polypharmacy-related adverse events in the geriatric population.
Q11: A pregnant patient at 28 weeks gestation requires pharmacologic treatment for hypertension.
Which of the following medications is considered first-line and safest in pregnancy?
A. Lisinopril, an ACE inhibitor.
B. Losartan, an ARB.
C. Methyldopa, a central alpha-2 agonist. [CORRECT]
D. Warfarin, an anticoagulant.
Correct Answer: C
Rationale: Methyldopa is the preferred first-line antihypertensive in pregnancy due to extensive safety data showing
no teratogenicity or fetal harm. It acts centrally as an alpha-2 agonist. Choice A and B (ACE inhibitors and ARBs)
are contraindicated in pregnancy—particularly in the second and third trimesters—due to fetotoxicity (renal
agenesis, oligohydramnios, hypocalvaria). Choice D (warfarin) is a known teratogen causing warfarin embryopathy.
Under the FDA Pregnancy and Lactation Labeling Rule (PLLR), medications are evaluated based on risk summary
rather than letter categories.
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