Wilkes NSG 533 Advanced Pharmacology - Exam 1
Practice Bank |Core Topics: Pharmacokinetics,
Autonomic Pharmacology, CNS Drugs,
Cardiovascular Drugs
SECTION 1: PHARMACOKINETICS & PHARMACODYNAMICS (Questions 1-40)
Question 1
A patient with chronic kidney disease (Stage 4) is prescribed a medication that is
70% renally excreted. The prescriber should anticipate:
A) Increasing the loading dose
B) Decreasing the maintenance dose
C) Shortening the dosing interval
D) No change in dosing
Correct Answer: B
Rationale: Reduced renal clearance requires lower maintenance doses or longer
intervals to prevent accumulation. Loading doses typically remain unchanged as
they distribute into volume of distribution.
Question 2
Which property of a drug would result in the longest duration of action after a
single intravenous dose?
A) High hepatic extraction ratio
B) Large volume of distribution
C) Short elimination half-life
D) Rapid renal tubular secretion
Correct Answer: B
Rationale: Large Vd means drug is extensively distributed into tissues, creating a
reservoir that slowly releases drug back into circulation, prolonging duration.
Question 3
A medication follows first-order elimination kinetics. After four half-lives, what
percentage of the original dose remains in the body?
1|Page
,A) 50%
B) 25%
C) 12.5%
D) 6.25%
Correct Answer: D
*Rationale: After 1 half-life: 50%; 2: 25%; 3: 12.5%; 4: 6.25%; 5: 3.125%*
Question 4
Which cytochrome P450 enzyme is most commonly involved in clinically
significant drug interactions?
A) CYP1A2
B) CYP2C9
C) CYP2D6
D) CYP3A4
Correct Answer: D
Rationale: CYP3A4 metabolizes >50% of all prescribed drugs, including statins,
calcium channel blockers, benzodiazepines, and many others.
Question 5
A patient is a poor metabolizer of CYP2D6 substrates. Which medication would
require a significant dose reduction to avoid toxicity?
A) Omeprazole
B) Warfarin
C) Codeine
D) Losartan
Correct Answer: C
*Rationale: Codeine is a prodrug requiring CYP2D6-mediated conversion to
morphine. Poor metabolizers get minimal analgesia, NOT toxicity. Wait—this asks
for dose reduction to avoid toxicity—actually poor metabolizers would have
reduced effect from codeine. Let me correct: The question should say "which
would cause toxicity?" Fluoxetine or metoprolol would be better examples. For
this question, the answer is none of the above for toxicity from poor metabolism.
I'll adjust.*
2|Page
,Question 5:
Which medication would most likely cause toxicity in a CYP2D6 poor metabolizer?
A) Codeine (reduced effect)
B) Metoprolol (increased beta-blockade)
C) Omeprazole (no change)
D) Warfarin (no change)
Correct Answer: B
*Rationale: CYP2D6 poor metabolizers have reduced clearance of metoprolol,
leading to elevated levels, excessive beta-blockade, bradycardia, and
hypotension.*
Question 6
A drug with high plasma protein binding (98%) is displaced by a second drug.
What is the most likely clinical consequence?
A) Transient increase in free drug concentration
B) Permanent decrease in drug efficacy
C) Immediate drug toxicity requiring dialysis
D) No significant change
Correct Answer: A
Rationale: Displacement increases free fraction transiently because the displaced
drug is rapidly redistributed and cleared. The clinical effect is usually mild and self-
limited.
Question 7
The therapeutic index (TI) of a drug is calculated as:
A) ED50/TD50
B) TD50/ED50
C) LD50/ED50
D) ED50/LD50
Correct Answer: C
*Rationale: TI = LD50/ED50 (in animals) or TD50/ED50 (in humans). Higher TI
indicates wider safety margin.*
Question 8
Which drug demonstrates zero-order elimination kinetics?
3|Page
, A) Phenytoin
B) Lithium
C) Ethanol
D) All of the above
Correct Answer: D
Rationale: Phenytoin, ethanol, high-dose aspirin, and heparin follow zero-order
kinetics at therapeutic concentrations—constant amount eliminated per unit time
regardless of concentration.
Question 9
A patient's medication has a half-life of 24 hours. Approximately how many days
will it take to reach steady state?
A) 2 days
B) 5 days
C) 7 days
D) 10 days
Correct Answer: B
*Rationale: Steady state reaches 94% after 4 half-lives (4 days) and 97% after 5
half-lives (5 days).*
Question 10
Which factor would INCREASE the volume of distribution of a lipophilic drug?
A) Obesity
B) Dehydration
C) Advanced age
D) Renal failure
Correct Answer: A
Rationale: Increased adipose tissue in obesity provides additional storage sites for
lipophilic drugs, increasing Vd.
Question 11
A drug is a weak acid with a pKa of 4.5. In which body fluid will it be MOST ionized
and thus trapped?
A) Stomach fluid (pH 1.5)
B) Blood (pH 7.4)
4|Page
Practice Bank |Core Topics: Pharmacokinetics,
Autonomic Pharmacology, CNS Drugs,
Cardiovascular Drugs
SECTION 1: PHARMACOKINETICS & PHARMACODYNAMICS (Questions 1-40)
Question 1
A patient with chronic kidney disease (Stage 4) is prescribed a medication that is
70% renally excreted. The prescriber should anticipate:
A) Increasing the loading dose
B) Decreasing the maintenance dose
C) Shortening the dosing interval
D) No change in dosing
Correct Answer: B
Rationale: Reduced renal clearance requires lower maintenance doses or longer
intervals to prevent accumulation. Loading doses typically remain unchanged as
they distribute into volume of distribution.
Question 2
Which property of a drug would result in the longest duration of action after a
single intravenous dose?
A) High hepatic extraction ratio
B) Large volume of distribution
C) Short elimination half-life
D) Rapid renal tubular secretion
Correct Answer: B
Rationale: Large Vd means drug is extensively distributed into tissues, creating a
reservoir that slowly releases drug back into circulation, prolonging duration.
Question 3
A medication follows first-order elimination kinetics. After four half-lives, what
percentage of the original dose remains in the body?
1|Page
,A) 50%
B) 25%
C) 12.5%
D) 6.25%
Correct Answer: D
*Rationale: After 1 half-life: 50%; 2: 25%; 3: 12.5%; 4: 6.25%; 5: 3.125%*
Question 4
Which cytochrome P450 enzyme is most commonly involved in clinically
significant drug interactions?
A) CYP1A2
B) CYP2C9
C) CYP2D6
D) CYP3A4
Correct Answer: D
Rationale: CYP3A4 metabolizes >50% of all prescribed drugs, including statins,
calcium channel blockers, benzodiazepines, and many others.
Question 5
A patient is a poor metabolizer of CYP2D6 substrates. Which medication would
require a significant dose reduction to avoid toxicity?
A) Omeprazole
B) Warfarin
C) Codeine
D) Losartan
Correct Answer: C
*Rationale: Codeine is a prodrug requiring CYP2D6-mediated conversion to
morphine. Poor metabolizers get minimal analgesia, NOT toxicity. Wait—this asks
for dose reduction to avoid toxicity—actually poor metabolizers would have
reduced effect from codeine. Let me correct: The question should say "which
would cause toxicity?" Fluoxetine or metoprolol would be better examples. For
this question, the answer is none of the above for toxicity from poor metabolism.
I'll adjust.*
2|Page
,Question 5:
Which medication would most likely cause toxicity in a CYP2D6 poor metabolizer?
A) Codeine (reduced effect)
B) Metoprolol (increased beta-blockade)
C) Omeprazole (no change)
D) Warfarin (no change)
Correct Answer: B
*Rationale: CYP2D6 poor metabolizers have reduced clearance of metoprolol,
leading to elevated levels, excessive beta-blockade, bradycardia, and
hypotension.*
Question 6
A drug with high plasma protein binding (98%) is displaced by a second drug.
What is the most likely clinical consequence?
A) Transient increase in free drug concentration
B) Permanent decrease in drug efficacy
C) Immediate drug toxicity requiring dialysis
D) No significant change
Correct Answer: A
Rationale: Displacement increases free fraction transiently because the displaced
drug is rapidly redistributed and cleared. The clinical effect is usually mild and self-
limited.
Question 7
The therapeutic index (TI) of a drug is calculated as:
A) ED50/TD50
B) TD50/ED50
C) LD50/ED50
D) ED50/LD50
Correct Answer: C
*Rationale: TI = LD50/ED50 (in animals) or TD50/ED50 (in humans). Higher TI
indicates wider safety margin.*
Question 8
Which drug demonstrates zero-order elimination kinetics?
3|Page
, A) Phenytoin
B) Lithium
C) Ethanol
D) All of the above
Correct Answer: D
Rationale: Phenytoin, ethanol, high-dose aspirin, and heparin follow zero-order
kinetics at therapeutic concentrations—constant amount eliminated per unit time
regardless of concentration.
Question 9
A patient's medication has a half-life of 24 hours. Approximately how many days
will it take to reach steady state?
A) 2 days
B) 5 days
C) 7 days
D) 10 days
Correct Answer: B
*Rationale: Steady state reaches 94% after 4 half-lives (4 days) and 97% after 5
half-lives (5 days).*
Question 10
Which factor would INCREASE the volume of distribution of a lipophilic drug?
A) Obesity
B) Dehydration
C) Advanced age
D) Renal failure
Correct Answer: A
Rationale: Increased adipose tissue in obesity provides additional storage sites for
lipophilic drugs, increasing Vd.
Question 11
A drug is a weak acid with a pKa of 4.5. In which body fluid will it be MOST ionized
and thus trapped?
A) Stomach fluid (pH 1.5)
B) Blood (pH 7.4)
4|Page
