NR 568 FINAL EXAM PREP 2026 | ADVANCED
PHARMACOLOGY QUESTIONS WITH ANSWERS &
RATIONALES NURSING STUDY GUIDE | VERSIONS A,
B AND C
Pass your psychiatric-mental health nurse practitioner advanced
pharmacology barrier with this ultimate 2026 NR 568 final exam
preparation package containing Versions A, B, and C. This
premium multi-version study guide features high-yield practice
questions paired with 100% verified answers and rigorous,
evidence-based clinical rationales. It is an indispensable resource
for graduate nursing students looking to master complex
psychotropic mechanisms, prescribing guidelines across the
lifespan, drug-drug interactions, and secure an A+ grade.
SECTION A: PHARMACOKINETICS &
PHARMACODYNAMICS IN AGING ADULTS (Questions
1-40)
Question 1
A 70-year-old patient with heart failure is started on digoxin. Which age-
related change in pharmacokinetics most increases the risk of toxicity?
,A. Decreased hepatic first-pass metabolism
B. Increased volume of distribution for water-soluble drugs
C. Decreased renal clearance of digoxin
D. Enhanced glomerular filtration rate
✅ Correct Answer: C. Decreased renal clearance of digoxin
Rationale: Renal clearance declines with age, reducing digoxin elimination .
Digoxin is primarily renally excreted; acute kidney injury or age-related
decline in renal function reduces clearance, increasing the risk of toxicity .
Dose adjustment based on renal function and monitoring of digoxin levels is
essential in older adults. A normal GFR does not guarantee normal drug
handling in elderly patients.
Question 2
A patient with a genetic polymorphism resulting in CYP2D6 poor
metabolizer phenotype is prescribed codeine for pain. What is the most
likely outcome?
A. Little to no analgesic effect due to inability to convert codeine to
morphine
B. Increased risk of respiratory depression from rapid conversion to
morphine
C. Prolonged half-life of codeine but normal analgesia
D. Increased risk of serotonin syndrome
✅ Correct Answer: A. Little to no analgesic effect due to inability to
convert codeine to morphine
Rationale: Codeine is a prodrug requiring CYP2D6 to convert to its active
metabolite, morphine . Poor metabolizers have reduced or absent analgesia
because they cannot effectively convert codeine to its active form. Rapid
metabolizers are at risk for toxicity. CYP2D6 is also involved in metabolism of
many other drugs including antidepressants and antipsychotics.
,Question 3
A patient is receiving a drug that is a weak base (pKa 8.5). Which of the
following would increase its renal excretion?
A. Alkalinizing the urine (increasing pH)
B. Acidifying the urine (decreasing pH)
C. Increasing urine flow rate only
D. Decreasing urine flow rate
✅ Correct Answer: B. Acidifying the urine (decreasing pH)
Rationale: Weak bases are ionized (and less reabsorbed) in acidic urine;
acidification traps the drug in urine, enhancing excretion . This principle is
known as "ion trapping." Weak acids (e.g., aspirin) are better excreted in
alkaline urine. The Henderson-Hasselbalch equation governs this
relationship: for weak bases, decreasing urinary pH increases the proportion
of ionized (charged) drug that cannot cross lipid membranes and is excreted.
Question 4
A patient with hepatic cirrhosis has a reduced ability to metabolize drugs
via phase I reactions. Which drug would be most affected?
A. Lorazepam (primarily phase II glucuronidation)
B. Phenytoin (primarily phase I oxidation)
C. Acetaminophen at therapeutic doses (phase II)
D. Morphine (phase II)
✅ Correct Answer: B. Phenytoin (primarily phase I oxidation)
Rationale: Phenytoin undergoes extensive hepatic oxidation (CYP450);
cirrhosis impairs phase I more than phase II, leading to accumulation and
toxicity . Phase I reactions (oxidation, reduction, hydrolysis) are more
, susceptible to age-related and disease-related decline than phase II
(conjugation) reactions. Lorazepam, morphine, and acetaminophen rely on
phase II glucuronidation, making them safer in hepatic impairment.
Question 5
A patient is started on a drug with a narrow therapeutic index. The nurse
practitioner orders therapeutic drug monitoring. Which principle best
justifies this?
A. Small changes in dose or clearance can lead to toxicity or treatment
failure
B. All drugs require monitoring regardless of index
C. The drug has a wide safety margin
D. Monitoring is only needed for intravenous drugs
✅ Correct Answer: A. Small changes in dose or clearance can lead to
toxicity or treatment failure
Rationale: Narrow therapeutic index drugs (e.g., warfarin, phenytoin, digoxin)
have small margins between efficacy and toxicity, requiring monitoring . Even
small changes in renal or hepatic function, drug interactions, or patient
adherence can push levels into toxic or subtherapeutic ranges. Examples
include: lithium (0.6-1.2 mEq/L), digoxin (0.8-2.0 ng/mL), and phenytoin (10-
20 mcg/mL).
Question 6
A patient is taking a drug that is a substrate of P-glycoprotein (P-gp).
Which co-administered drug could increase the oral bioavailability of this
substrate?
PHARMACOLOGY QUESTIONS WITH ANSWERS &
RATIONALES NURSING STUDY GUIDE | VERSIONS A,
B AND C
Pass your psychiatric-mental health nurse practitioner advanced
pharmacology barrier with this ultimate 2026 NR 568 final exam
preparation package containing Versions A, B, and C. This
premium multi-version study guide features high-yield practice
questions paired with 100% verified answers and rigorous,
evidence-based clinical rationales. It is an indispensable resource
for graduate nursing students looking to master complex
psychotropic mechanisms, prescribing guidelines across the
lifespan, drug-drug interactions, and secure an A+ grade.
SECTION A: PHARMACOKINETICS &
PHARMACODYNAMICS IN AGING ADULTS (Questions
1-40)
Question 1
A 70-year-old patient with heart failure is started on digoxin. Which age-
related change in pharmacokinetics most increases the risk of toxicity?
,A. Decreased hepatic first-pass metabolism
B. Increased volume of distribution for water-soluble drugs
C. Decreased renal clearance of digoxin
D. Enhanced glomerular filtration rate
✅ Correct Answer: C. Decreased renal clearance of digoxin
Rationale: Renal clearance declines with age, reducing digoxin elimination .
Digoxin is primarily renally excreted; acute kidney injury or age-related
decline in renal function reduces clearance, increasing the risk of toxicity .
Dose adjustment based on renal function and monitoring of digoxin levels is
essential in older adults. A normal GFR does not guarantee normal drug
handling in elderly patients.
Question 2
A patient with a genetic polymorphism resulting in CYP2D6 poor
metabolizer phenotype is prescribed codeine for pain. What is the most
likely outcome?
A. Little to no analgesic effect due to inability to convert codeine to
morphine
B. Increased risk of respiratory depression from rapid conversion to
morphine
C. Prolonged half-life of codeine but normal analgesia
D. Increased risk of serotonin syndrome
✅ Correct Answer: A. Little to no analgesic effect due to inability to
convert codeine to morphine
Rationale: Codeine is a prodrug requiring CYP2D6 to convert to its active
metabolite, morphine . Poor metabolizers have reduced or absent analgesia
because they cannot effectively convert codeine to its active form. Rapid
metabolizers are at risk for toxicity. CYP2D6 is also involved in metabolism of
many other drugs including antidepressants and antipsychotics.
,Question 3
A patient is receiving a drug that is a weak base (pKa 8.5). Which of the
following would increase its renal excretion?
A. Alkalinizing the urine (increasing pH)
B. Acidifying the urine (decreasing pH)
C. Increasing urine flow rate only
D. Decreasing urine flow rate
✅ Correct Answer: B. Acidifying the urine (decreasing pH)
Rationale: Weak bases are ionized (and less reabsorbed) in acidic urine;
acidification traps the drug in urine, enhancing excretion . This principle is
known as "ion trapping." Weak acids (e.g., aspirin) are better excreted in
alkaline urine. The Henderson-Hasselbalch equation governs this
relationship: for weak bases, decreasing urinary pH increases the proportion
of ionized (charged) drug that cannot cross lipid membranes and is excreted.
Question 4
A patient with hepatic cirrhosis has a reduced ability to metabolize drugs
via phase I reactions. Which drug would be most affected?
A. Lorazepam (primarily phase II glucuronidation)
B. Phenytoin (primarily phase I oxidation)
C. Acetaminophen at therapeutic doses (phase II)
D. Morphine (phase II)
✅ Correct Answer: B. Phenytoin (primarily phase I oxidation)
Rationale: Phenytoin undergoes extensive hepatic oxidation (CYP450);
cirrhosis impairs phase I more than phase II, leading to accumulation and
toxicity . Phase I reactions (oxidation, reduction, hydrolysis) are more
, susceptible to age-related and disease-related decline than phase II
(conjugation) reactions. Lorazepam, morphine, and acetaminophen rely on
phase II glucuronidation, making them safer in hepatic impairment.
Question 5
A patient is started on a drug with a narrow therapeutic index. The nurse
practitioner orders therapeutic drug monitoring. Which principle best
justifies this?
A. Small changes in dose or clearance can lead to toxicity or treatment
failure
B. All drugs require monitoring regardless of index
C. The drug has a wide safety margin
D. Monitoring is only needed for intravenous drugs
✅ Correct Answer: A. Small changes in dose or clearance can lead to
toxicity or treatment failure
Rationale: Narrow therapeutic index drugs (e.g., warfarin, phenytoin, digoxin)
have small margins between efficacy and toxicity, requiring monitoring . Even
small changes in renal or hepatic function, drug interactions, or patient
adherence can push levels into toxic or subtherapeutic ranges. Examples
include: lithium (0.6-1.2 mEq/L), digoxin (0.8-2.0 ng/mL), and phenytoin (10-
20 mcg/mL).
Question 6
A patient is taking a drug that is a substrate of P-glycoprotein (P-gp).
Which co-administered drug could increase the oral bioavailability of this
substrate?
