NURS 5663 ADVANCED
PHARMACOLOGY: WEEK 2
COMPREHENSIVE QUESTIONS AND
ANSWERS
1. Which pharmacokinetic process is primarily affected by the ‘first-pass effect’ following oral
administration?
A. Hepatic metabolism
B. Renal excretion
C. Distribution to the brain
D. Pulmonary ventilation
Answer: A
Conceptual Explanation: The first-pass effect refers to the rapid hepatic metabolism of a
drug as it passes through the liver via the portal vein after absorption from the
gastrointestinal tract, significantly reducing the amount of active drug that reaches
systemic circulation.
,2. A patient with hypoalbuminemia is prescribed a highly protein-bound drug. How does this
condition affect the drug’s pharmacokinetics?
A. Decreased free drug concentration
B. Accelerated renal filtration of the bound drug
C. Decreased volume of distribution
D. Increased risk of toxicity due to higher free drug levels
Answer: D
Conceptual Explanation: Low albumin levels mean fewer binding sites are available for
the drug. This results in an increased concentration of ‘free’ or unbound drug, which is the
pharmacologically active form, thereby increasing the risk of toxicity.
3. In a dose-response curve, what does the term ‘efficacy’ represent?
A. The dose required to produce 50% of the maximal effect
B. The maximum effect a drug can produce regardless of dose
C. The affinity of the drug for its receptor
D. The speed at which the drug reaches its target tissue
Answer: B
Conceptual Explanation: Efficacy, or intrinsic activity, is the maximum response a drug
can produce. It is represented by the plateau of the dose-response curve. It is clinically
more important than potency.
, 4. A drug has a half-life of 6 hours. If the initial plasma concentration is 100 mg/L, what will
be the concentration after 24 hours (assuming first-order kinetics)?
A. 25 mg/L
B. 6.25 mg/L
C. 12.5 mg/L
D. 3.125 mg/L
Answer: B
Conceptual Explanation: 24 hours represents four half-lives (24/6 = 4). After one half-
life: 50 mg/L; two: 25 mg/L; three: 12.5 mg/L; four: 6.25 mg/L.
5. Which cytochrome P450 enzyme is responsible for the metabolism of approximately 50%
of all clinically used drugs?
A. CYP2D6
B. CYP3A4
C. CYP1A2
D. CYP2C19
Answer: B
Conceptual Explanation: CYP3A4 is the most abundant CYP enzyme in the liver and is
involved in the metabolism of the largest variety of drugs.
PHARMACOLOGY: WEEK 2
COMPREHENSIVE QUESTIONS AND
ANSWERS
1. Which pharmacokinetic process is primarily affected by the ‘first-pass effect’ following oral
administration?
A. Hepatic metabolism
B. Renal excretion
C. Distribution to the brain
D. Pulmonary ventilation
Answer: A
Conceptual Explanation: The first-pass effect refers to the rapid hepatic metabolism of a
drug as it passes through the liver via the portal vein after absorption from the
gastrointestinal tract, significantly reducing the amount of active drug that reaches
systemic circulation.
,2. A patient with hypoalbuminemia is prescribed a highly protein-bound drug. How does this
condition affect the drug’s pharmacokinetics?
A. Decreased free drug concentration
B. Accelerated renal filtration of the bound drug
C. Decreased volume of distribution
D. Increased risk of toxicity due to higher free drug levels
Answer: D
Conceptual Explanation: Low albumin levels mean fewer binding sites are available for
the drug. This results in an increased concentration of ‘free’ or unbound drug, which is the
pharmacologically active form, thereby increasing the risk of toxicity.
3. In a dose-response curve, what does the term ‘efficacy’ represent?
A. The dose required to produce 50% of the maximal effect
B. The maximum effect a drug can produce regardless of dose
C. The affinity of the drug for its receptor
D. The speed at which the drug reaches its target tissue
Answer: B
Conceptual Explanation: Efficacy, or intrinsic activity, is the maximum response a drug
can produce. It is represented by the plateau of the dose-response curve. It is clinically
more important than potency.
, 4. A drug has a half-life of 6 hours. If the initial plasma concentration is 100 mg/L, what will
be the concentration after 24 hours (assuming first-order kinetics)?
A. 25 mg/L
B. 6.25 mg/L
C. 12.5 mg/L
D. 3.125 mg/L
Answer: B
Conceptual Explanation: 24 hours represents four half-lives (24/6 = 4). After one half-
life: 50 mg/L; two: 25 mg/L; three: 12.5 mg/L; four: 6.25 mg/L.
5. Which cytochrome P450 enzyme is responsible for the metabolism of approximately 50%
of all clinically used drugs?
A. CYP2D6
B. CYP3A4
C. CYP1A2
D. CYP2C19
Answer: B
Conceptual Explanation: CYP3A4 is the most abundant CYP enzyme in the liver and is
involved in the metabolism of the largest variety of drugs.
