NR 565 Advanced Pharmacology Week 8
Final Exam | Actual Review & Detailed
Rationales
SECTION 1: PHARMACOKINETICS, PHARMACODYNAMICS,
AND PHARMACOGENOMICS (Questions 1–35)
1. A patient asks why the same dose of a drug affects people differently. Which
concept best explains this variability?
A) Pharmacodynamics
B) Pharmacokinetics
C) Pharmacogenomics
D) Bioavailability
Correct Answer: C) Pharmacogenomics
Rationale: Pharmacogenomics studies how genetic variations influence drug response,
metabolism, and toxicity, explaining interpatient variability. Pharmacodynamics is what
the drug does to the body; pharmacokinetics is what the body does to the drug;
bioavailability is the fraction of drug reaching systemic circulation.
2. Which process describes the movement of a drug from its site of administration
into the systemic circulation?
A) Distribution
,B) Metabolism
C) Absorption
D) Excretion
Correct Answer: C) Absorption
Rationale: Absorption is the movement of drug from the administration site into the
bloodstream. Distribution is movement to tissues; metabolism is biotransformation;
excretion is elimination.
3. A patient with cirrhosis has increased sensitivity to drugs metabolized by the
liver. Which pharmacokinetic change best explains this?
A) Increased first-pass metabolism
B) Reduced first-pass hepatic metabolism and portosystemic shunting
C) Increased renal clearance
D) Decreased protein binding
Correct Answer: B) Reduced first-pass hepatic metabolism and portosystemic
shunting
Rationale: Cirrhosis damages hepatocytes and causes portosystemic shunting, reducing
first-pass metabolism and increasing drug bioavailability and toxicity risk. Increased first-
pass metabolism and increased renal clearance would lower drug levels; decreased protein
binding increases free drug but is not the primary mechanism described.
4. Which CYP450 enzyme is responsible for metabolizing the largest number of
drugs?
A) CYP2D6
B) CYP3A4
C) CYP2C9
D) CYP1A2
Correct Answer: B) CYP3A4
,Rationale: CYP3A4 metabolizes approximately 50% of all drugs, making it the most
clinically significant CYP450 enzyme for drug interactions. CYP2D6, CYP2C9, and CYP1A2
metabolize smaller but important subsets.
5. A patient taking warfarin is prescribed amiodarone. What is the primary
concern?
A) Reduced warfarin absorption
B) Increased INR and bleeding risk
C) Hyperkalemia
D) Thyroid dysfunction
Correct Answer: B) Increased INR and bleeding risk
Rationale: Amiodarone is a potent CYP2C9 inhibitor that reduces warfarin metabolism,
increasing INR and bleeding risk. It does not reduce warfarin absorption; hyperkalemia
and thyroid dysfunction are amiodarone effects but are not the primary warfarin
interaction concern.
6. Which statement best describes a drug with a narrow therapeutic index?
A) It has few side effects.
B) Small changes in dose or blood level can cause toxicity or therapeutic failure.
C) It is safe in pregnancy.
D) It has no drug interactions.
Correct Answer: B) Small changes in dose or blood level can cause toxicity or
therapeutic failure.
Rationale: Narrow therapeutic index drugs (e.g., warfarin, digoxin, lithium, phenytoin)
require careful dosing and monitoring because small fluctuations can lead to toxicity or
loss of efficacy. They often have many side effects and interactions.
, 7. A patient is a CYP2D6 poor metabolizer. Which opioid should be avoided?
A) Morphine
B) Codeine
C) Fentanyl
D) Hydromorphone
Correct Answer: B) Codeine
Rationale: Codeine is a prodrug requiring CYP2D6 conversion to morphine. Poor
metabolizers may receive inadequate analgesia, while ultrarapid metabolizers risk toxicity.
Morphine, fentanyl, and hydromorphone do not rely on CYP2D6 activation.
8. Which phase of pharmacokinetics involves drug movement from the
bloodstream to tissues?
A) Absorption
B) Distribution
C) Metabolism
D) Excretion
Correct Answer: B) Distribution
Rationale: Distribution is the reversible movement of drug from blood to interstitial and
intracellular fluids. It depends on blood flow, protein binding, and lipid solubility.
9. A drug that is highly protein-bound will have which characteristic?
A) A large volume of distribution
B) A small free-drug fraction
C) Rapid renal excretion
D) High hepatic clearance
Correct Answer: B) A small free-drug fraction
Rationale: Highly protein-bound drugs have less free drug available for receptor binding,
metabolism, and excretion. This can lead to drug interactions when two highly bound
drugs compete for binding sites.
Final Exam | Actual Review & Detailed
Rationales
SECTION 1: PHARMACOKINETICS, PHARMACODYNAMICS,
AND PHARMACOGENOMICS (Questions 1–35)
1. A patient asks why the same dose of a drug affects people differently. Which
concept best explains this variability?
A) Pharmacodynamics
B) Pharmacokinetics
C) Pharmacogenomics
D) Bioavailability
Correct Answer: C) Pharmacogenomics
Rationale: Pharmacogenomics studies how genetic variations influence drug response,
metabolism, and toxicity, explaining interpatient variability. Pharmacodynamics is what
the drug does to the body; pharmacokinetics is what the body does to the drug;
bioavailability is the fraction of drug reaching systemic circulation.
2. Which process describes the movement of a drug from its site of administration
into the systemic circulation?
A) Distribution
,B) Metabolism
C) Absorption
D) Excretion
Correct Answer: C) Absorption
Rationale: Absorption is the movement of drug from the administration site into the
bloodstream. Distribution is movement to tissues; metabolism is biotransformation;
excretion is elimination.
3. A patient with cirrhosis has increased sensitivity to drugs metabolized by the
liver. Which pharmacokinetic change best explains this?
A) Increased first-pass metabolism
B) Reduced first-pass hepatic metabolism and portosystemic shunting
C) Increased renal clearance
D) Decreased protein binding
Correct Answer: B) Reduced first-pass hepatic metabolism and portosystemic
shunting
Rationale: Cirrhosis damages hepatocytes and causes portosystemic shunting, reducing
first-pass metabolism and increasing drug bioavailability and toxicity risk. Increased first-
pass metabolism and increased renal clearance would lower drug levels; decreased protein
binding increases free drug but is not the primary mechanism described.
4. Which CYP450 enzyme is responsible for metabolizing the largest number of
drugs?
A) CYP2D6
B) CYP3A4
C) CYP2C9
D) CYP1A2
Correct Answer: B) CYP3A4
,Rationale: CYP3A4 metabolizes approximately 50% of all drugs, making it the most
clinically significant CYP450 enzyme for drug interactions. CYP2D6, CYP2C9, and CYP1A2
metabolize smaller but important subsets.
5. A patient taking warfarin is prescribed amiodarone. What is the primary
concern?
A) Reduced warfarin absorption
B) Increased INR and bleeding risk
C) Hyperkalemia
D) Thyroid dysfunction
Correct Answer: B) Increased INR and bleeding risk
Rationale: Amiodarone is a potent CYP2C9 inhibitor that reduces warfarin metabolism,
increasing INR and bleeding risk. It does not reduce warfarin absorption; hyperkalemia
and thyroid dysfunction are amiodarone effects but are not the primary warfarin
interaction concern.
6. Which statement best describes a drug with a narrow therapeutic index?
A) It has few side effects.
B) Small changes in dose or blood level can cause toxicity or therapeutic failure.
C) It is safe in pregnancy.
D) It has no drug interactions.
Correct Answer: B) Small changes in dose or blood level can cause toxicity or
therapeutic failure.
Rationale: Narrow therapeutic index drugs (e.g., warfarin, digoxin, lithium, phenytoin)
require careful dosing and monitoring because small fluctuations can lead to toxicity or
loss of efficacy. They often have many side effects and interactions.
, 7. A patient is a CYP2D6 poor metabolizer. Which opioid should be avoided?
A) Morphine
B) Codeine
C) Fentanyl
D) Hydromorphone
Correct Answer: B) Codeine
Rationale: Codeine is a prodrug requiring CYP2D6 conversion to morphine. Poor
metabolizers may receive inadequate analgesia, while ultrarapid metabolizers risk toxicity.
Morphine, fentanyl, and hydromorphone do not rely on CYP2D6 activation.
8. Which phase of pharmacokinetics involves drug movement from the
bloodstream to tissues?
A) Absorption
B) Distribution
C) Metabolism
D) Excretion
Correct Answer: B) Distribution
Rationale: Distribution is the reversible movement of drug from blood to interstitial and
intracellular fluids. It depends on blood flow, protein binding, and lipid solubility.
9. A drug that is highly protein-bound will have which characteristic?
A) A large volume of distribution
B) A small free-drug fraction
C) Rapid renal excretion
D) High hepatic clearance
Correct Answer: B) A small free-drug fraction
Rationale: Highly protein-bound drugs have less free drug available for receptor binding,
metabolism, and excretion. This can lead to drug interactions when two highly bound
drugs compete for binding sites.
