WGU D116 ADVANCED
PHARMACOLOGY COMPREHENSIVE
ASSESSMENT QUESTIONS AND
ANSWERS
1. A patient is prescribed Rifampin for tuberculosis. The nurse practitioner understands that
Rifampin is a potent inducer of the CYP3A4 enzyme system. How will this likely affect a co-
administered drug that is a substrate of the same enzyme?
A. The blood levels of the substrate drug will decrease, potentially leading to therapeutic
failure.
B. The blood levels of the substrate drug will increase, leading to potential toxicity.
C. There will be no change in the metabolism of the substrate drug.
D. Rifampin will inhibit the renal excretion of the substrate drug.
Answer: A
Conceptual Explanation: Enzyme inducers like Rifampin increase the rate of drug
metabolism by the CYP450 system. When the metabolism of a substrate drug is increased,
its plasma concentration decreases, which can lead to sub-therapeutic levels.
,2. Which of the following describes the ‘First-Pass Effect’ in pharmacology?
A. The extensive metabolism of an oral drug by the liver before it reaches systemic
circulation.
B. The excretion of a drug through the kidneys during the first circulatory cycle.
C. The initial distribution of a drug to the highly perfused organs like the brain and heart.
D. The binding of a drug to plasma proteins immediately after absorption.
Answer: A
Conceptual Explanation: The first-pass effect refers to the rapid hepatic metabolism of an
orally administered drug that occurs before the drug reaches the systemic circulation, often
significantly reducing bioavailability.
3. A 65-year-old male with a history of bilateral renal artery stenosis is diagnosed with
hypertension. Which class of antihypertensive medications is generally contraindicated in this
patient?
A. ACE Inhibitors
B. Thiazide Diuretics
C. Calcium Channel Blockers
D. Beta-Blockers
Answer: A
, Conceptual Explanation: ACE Inhibitors (and ARBs) are contraindicated in patients with
bilateral renal artery stenosis because they can cause a sharp decline in glomerular
filtration rate (GFR) and lead to acute renal failure.
4. A patient taking Digoxin for heart failure presents with nausea, vomiting, and seeing
yellow-green halos around lights. Which electrolyte imbalance most significantly increases
the risk of this toxicity?
A. Hyperkalemia
B. Hyponatremia
C. Hypercalcemia
D. Hypokalemia
Answer: D
Conceptual Explanation: Hypokalemia increases the risk of digoxin toxicity because
digoxin competes with potassium for binding at the Na+/K+-ATPase pump. Lower
potassium levels allow more digoxin to bind, enhancing its effects and toxicity.
5. A patient is being started on Warfarin for atrial fibrillation. What is the mechanism of
action of Warfarin?
A. Directly inhibits Thrombin (Factor IIa)
B. Directly inhibits Factor Xa in the final common pathway.
C. Activates Antithrombin III, which inactivates Factor Xa.
PHARMACOLOGY COMPREHENSIVE
ASSESSMENT QUESTIONS AND
ANSWERS
1. A patient is prescribed Rifampin for tuberculosis. The nurse practitioner understands that
Rifampin is a potent inducer of the CYP3A4 enzyme system. How will this likely affect a co-
administered drug that is a substrate of the same enzyme?
A. The blood levels of the substrate drug will decrease, potentially leading to therapeutic
failure.
B. The blood levels of the substrate drug will increase, leading to potential toxicity.
C. There will be no change in the metabolism of the substrate drug.
D. Rifampin will inhibit the renal excretion of the substrate drug.
Answer: A
Conceptual Explanation: Enzyme inducers like Rifampin increase the rate of drug
metabolism by the CYP450 system. When the metabolism of a substrate drug is increased,
its plasma concentration decreases, which can lead to sub-therapeutic levels.
,2. Which of the following describes the ‘First-Pass Effect’ in pharmacology?
A. The extensive metabolism of an oral drug by the liver before it reaches systemic
circulation.
B. The excretion of a drug through the kidneys during the first circulatory cycle.
C. The initial distribution of a drug to the highly perfused organs like the brain and heart.
D. The binding of a drug to plasma proteins immediately after absorption.
Answer: A
Conceptual Explanation: The first-pass effect refers to the rapid hepatic metabolism of an
orally administered drug that occurs before the drug reaches the systemic circulation, often
significantly reducing bioavailability.
3. A 65-year-old male with a history of bilateral renal artery stenosis is diagnosed with
hypertension. Which class of antihypertensive medications is generally contraindicated in this
patient?
A. ACE Inhibitors
B. Thiazide Diuretics
C. Calcium Channel Blockers
D. Beta-Blockers
Answer: A
, Conceptual Explanation: ACE Inhibitors (and ARBs) are contraindicated in patients with
bilateral renal artery stenosis because they can cause a sharp decline in glomerular
filtration rate (GFR) and lead to acute renal failure.
4. A patient taking Digoxin for heart failure presents with nausea, vomiting, and seeing
yellow-green halos around lights. Which electrolyte imbalance most significantly increases
the risk of this toxicity?
A. Hyperkalemia
B. Hyponatremia
C. Hypercalcemia
D. Hypokalemia
Answer: D
Conceptual Explanation: Hypokalemia increases the risk of digoxin toxicity because
digoxin competes with potassium for binding at the Na+/K+-ATPase pump. Lower
potassium levels allow more digoxin to bind, enhancing its effects and toxicity.
5. A patient is being started on Warfarin for atrial fibrillation. What is the mechanism of
action of Warfarin?
A. Directly inhibits Thrombin (Factor IIa)
B. Directly inhibits Factor Xa in the final common pathway.
C. Activates Antithrombin III, which inactivates Factor Xa.
