NSG 5240: Advanced Pharmacology
Comprehensive Examination | 120 Questions with Answers & Rationales
1. A patient with cirrhosis is started on a highly protein-bound medication. What
is the most likely pharmacokinetic consequence?
A. Decreased free drug concentration and reduced effect
B. Increased free drug concentration and risk of toxicity
C. No change because protein binding does not affect free fraction
D. Increased renal clearance of the drug
Correct Answer: B
Rationale: In cirrhosis, hepatic synthesis of albumin is reduced, leaving fewer binding
sites. This raises the unbound (free, active) fraction of highly protein-bound drugs,
increasing the risk of toxicity even when total drug levels appear normal.
2. Which route of administration avoids first-pass hepatic metabolism?
A. Oral
B. Sublingual
C. Rectal (upper portion)
D. Enteral feeding tube
Correct Answer: B
Rationale: Sublingual administration allows drug absorption directly into the systemic
venous circulation via the sublingual vein, bypassing the portal circulation and hepatic
first-pass metabolism, unlike oral or upper rectal routes.
3. A drug has a half-life of 6 hours. Approximately how long will it take to reach
steady-state concentration with regular dosing?
A. 6 hours
B. 12 hours
C. 24-30 hours
D. 48-60 hours
Correct Answer: C
Rationale: Steady state is reached after approximately 4-5 half-lives regardless of dose
or dosing interval. With a 6-hour half-life, 4-5 half-lives equal roughly 24-30 hours.
,4. Which factor most directly determines the loading dose of a medication?
A. Clearance
B. Volume of distribution
C. Half-life
D. Bioavailability only
Correct Answer: B
Rationale: Loading dose is calculated as (Vd x target concentration)/bioavailability.
Volume of distribution reflects how extensively a drug distributes into tissues versus
remaining in plasma, and is the primary determinant of the loading dose needed to
rapidly achieve a target plasma concentration.
5. A medication is a substrate of CYP3A4. Which co-administered agent is most
likely to increase its serum concentration to toxic levels?
A. Rifampin
B. Phenytoin
C. Grapefruit juice/ketoconazole
D. Carbamazepine
Correct Answer: C
Rationale: Ketoconazole and grapefruit juice are potent CYP3A4 inhibitors that reduce
first-pass and systemic metabolism of CYP3A4 substrates, raising plasma
concentrations. Rifampin, phenytoin, and carbamazepine are enzyme inducers that
would lower drug levels instead.
6. Which term best describes the fraction of an administered dose that reaches
systemic circulation unchanged?
A. Clearance
B. Bioavailability
C. Volume of distribution
D. Elimination rate constant
Correct Answer: B
Rationale: Bioavailability (F) is defined as the fraction of an administered dose of
unchanged drug that reaches systemic circulation; it is 100% for IV administration and
typically lower for oral agents due to incomplete absorption and first-pass metabolism.
,7. A neonate is prescribed a renally eliminated drug. Which physiologic feature
of neonates most affects dosing?
A. Increased glomerular filtration rate compared to adults
B. Immature renal function leading to prolonged drug half-life
C. Increased hepatic enzyme activity
D. Decreased total body water
Correct Answer: B
Rationale: Neonates have immature glomerular filtration and tubular secretion, which
prolongs the half-life of renally cleared drugs, necessitating lower doses or extended
dosing intervals to prevent accumulation and toxicity.
8. Which of the following best explains why elderly patients often require lower
drug doses?
A. Increased hepatic blood flow
B. Increased lean body mass
C. Decreased renal and hepatic clearance with increased fat-to-lean ratio
D. Decreased volume of distribution for all drugs
Correct Answer: C
Rationale: Aging is associated with declining renal and hepatic clearance, decreased
lean body mass, and increased body fat, which increases the volume of distribution for
lipophilic drugs and prolongs half-life, warranting dose reduction.
9. Zero-order kinetics differs from first-order kinetics in that:
A. A constant percentage of drug is eliminated per unit time
B. A constant amount of drug is eliminated per unit time regardless of concentration
C. Elimination rate increases proportionally with dose
D. Half-life remains constant across doses
Correct Answer: B
Rationale: In zero-order kinetics, elimination occurs at a constant rate (fixed amount
per unit time) because the elimination pathway is saturated, as seen with phenytoin,
alcohol, and high-dose aspirin. This differs from first-order kinetics, where a constant
fraction is eliminated per unit time.
, 10. A drug undergoing extensive first-pass metabolism would be expected to
have:
A. High oral bioavailability
B. Low oral bioavailability relative to IV dose
C. Identical IV and oral bioavailability
D. No hepatic involvement
Correct Answer: B
Rationale: Drugs with high first-pass hepatic metabolism are extensively metabolized
before reaching systemic circulation when given orally, resulting in low oral
bioavailability compared to the same dose given intravenously, which bypasses this
effect entirely.
11. A drug that binds to a receptor but produces a submaximal response even at
full receptor occupancy is termed a:
A. Full agonist
B. Partial agonist
C. Competitive antagonist
D. Inverse agonist
Correct Answer: B
Rationale: A partial agonist binds to and activates a receptor but cannot produce the
maximal effect achievable by a full agonist, even when all receptors are occupied, due
to lower intrinsic efficacy.
12. Which term describes the dose of a drug required to produce a therapeutic
effect in 50% of a population?
A. LD50
B. ED50
C. TD50
D. Therapeutic index
Correct Answer: B
Rationale: ED50 (median effective dose) is the dose at which 50% of the population
exhibits the specified therapeutic effect; it is used together with TD50 or LD50 to
calculate the therapeutic index.
Comprehensive Examination | 120 Questions with Answers & Rationales
1. A patient with cirrhosis is started on a highly protein-bound medication. What
is the most likely pharmacokinetic consequence?
A. Decreased free drug concentration and reduced effect
B. Increased free drug concentration and risk of toxicity
C. No change because protein binding does not affect free fraction
D. Increased renal clearance of the drug
Correct Answer: B
Rationale: In cirrhosis, hepatic synthesis of albumin is reduced, leaving fewer binding
sites. This raises the unbound (free, active) fraction of highly protein-bound drugs,
increasing the risk of toxicity even when total drug levels appear normal.
2. Which route of administration avoids first-pass hepatic metabolism?
A. Oral
B. Sublingual
C. Rectal (upper portion)
D. Enteral feeding tube
Correct Answer: B
Rationale: Sublingual administration allows drug absorption directly into the systemic
venous circulation via the sublingual vein, bypassing the portal circulation and hepatic
first-pass metabolism, unlike oral or upper rectal routes.
3. A drug has a half-life of 6 hours. Approximately how long will it take to reach
steady-state concentration with regular dosing?
A. 6 hours
B. 12 hours
C. 24-30 hours
D. 48-60 hours
Correct Answer: C
Rationale: Steady state is reached after approximately 4-5 half-lives regardless of dose
or dosing interval. With a 6-hour half-life, 4-5 half-lives equal roughly 24-30 hours.
,4. Which factor most directly determines the loading dose of a medication?
A. Clearance
B. Volume of distribution
C. Half-life
D. Bioavailability only
Correct Answer: B
Rationale: Loading dose is calculated as (Vd x target concentration)/bioavailability.
Volume of distribution reflects how extensively a drug distributes into tissues versus
remaining in plasma, and is the primary determinant of the loading dose needed to
rapidly achieve a target plasma concentration.
5. A medication is a substrate of CYP3A4. Which co-administered agent is most
likely to increase its serum concentration to toxic levels?
A. Rifampin
B. Phenytoin
C. Grapefruit juice/ketoconazole
D. Carbamazepine
Correct Answer: C
Rationale: Ketoconazole and grapefruit juice are potent CYP3A4 inhibitors that reduce
first-pass and systemic metabolism of CYP3A4 substrates, raising plasma
concentrations. Rifampin, phenytoin, and carbamazepine are enzyme inducers that
would lower drug levels instead.
6. Which term best describes the fraction of an administered dose that reaches
systemic circulation unchanged?
A. Clearance
B. Bioavailability
C. Volume of distribution
D. Elimination rate constant
Correct Answer: B
Rationale: Bioavailability (F) is defined as the fraction of an administered dose of
unchanged drug that reaches systemic circulation; it is 100% for IV administration and
typically lower for oral agents due to incomplete absorption and first-pass metabolism.
,7. A neonate is prescribed a renally eliminated drug. Which physiologic feature
of neonates most affects dosing?
A. Increased glomerular filtration rate compared to adults
B. Immature renal function leading to prolonged drug half-life
C. Increased hepatic enzyme activity
D. Decreased total body water
Correct Answer: B
Rationale: Neonates have immature glomerular filtration and tubular secretion, which
prolongs the half-life of renally cleared drugs, necessitating lower doses or extended
dosing intervals to prevent accumulation and toxicity.
8. Which of the following best explains why elderly patients often require lower
drug doses?
A. Increased hepatic blood flow
B. Increased lean body mass
C. Decreased renal and hepatic clearance with increased fat-to-lean ratio
D. Decreased volume of distribution for all drugs
Correct Answer: C
Rationale: Aging is associated with declining renal and hepatic clearance, decreased
lean body mass, and increased body fat, which increases the volume of distribution for
lipophilic drugs and prolongs half-life, warranting dose reduction.
9. Zero-order kinetics differs from first-order kinetics in that:
A. A constant percentage of drug is eliminated per unit time
B. A constant amount of drug is eliminated per unit time regardless of concentration
C. Elimination rate increases proportionally with dose
D. Half-life remains constant across doses
Correct Answer: B
Rationale: In zero-order kinetics, elimination occurs at a constant rate (fixed amount
per unit time) because the elimination pathway is saturated, as seen with phenytoin,
alcohol, and high-dose aspirin. This differs from first-order kinetics, where a constant
fraction is eliminated per unit time.
, 10. A drug undergoing extensive first-pass metabolism would be expected to
have:
A. High oral bioavailability
B. Low oral bioavailability relative to IV dose
C. Identical IV and oral bioavailability
D. No hepatic involvement
Correct Answer: B
Rationale: Drugs with high first-pass hepatic metabolism are extensively metabolized
before reaching systemic circulation when given orally, resulting in low oral
bioavailability compared to the same dose given intravenously, which bypasses this
effect entirely.
11. A drug that binds to a receptor but produces a submaximal response even at
full receptor occupancy is termed a:
A. Full agonist
B. Partial agonist
C. Competitive antagonist
D. Inverse agonist
Correct Answer: B
Rationale: A partial agonist binds to and activates a receptor but cannot produce the
maximal effect achievable by a full agonist, even when all receptors are occupied, due
to lower intrinsic efficacy.
12. Which term describes the dose of a drug required to produce a therapeutic
effect in 50% of a population?
A. LD50
B. ED50
C. TD50
D. Therapeutic index
Correct Answer: B
Rationale: ED50 (median effective dose) is the dose at which 50% of the population
exhibits the specified therapeutic effect; it is used together with TD50 or LD50 to
calculate the therapeutic index.
