NUR 600 Exam 2 | (2026) Pharmacology Questions | Clinical
Nursing (PDF) — 200 Questions
Section 1: Pharmacokinetics and Pharmacodynamics (Questions 1-20)
1. A drug follows first-order elimination kinetics and has a half-life of 6 hours. If a patient receives an intravenous
bolus dose of 500 mg, approximately how many milligrams remain in the body 18 hours after administration?
A) 125 mg
B) 62.5 mg
C) 31.25 mg
D) 250 mg
Answer: B
Rationale: First-order kinetics means half-life is constant. After 18 hours (3 half-lives), the amount remaining is 500
mg / 2^3 = 62.5 mg. Option A (125 mg) corresponds to 2 half-lives, C to 4 half-lives, D to 1 half-life.
2. A drug with a narrow therapeutic index is administered orally. Which of the following scenarios would most
likely result in a supratherapeutic concentration leading to toxicity?
A) Increased first-pass metabolism due to enzyme induction
B) Decreased protein binding leading to higher free fraction
C) Increased renal clearance due to diuretic use
D) Decreased gastric emptying time
Answer: B
Rationale: Decreased protein binding increases the free (active) drug concentration, potentially causing toxicity for
drugs with narrow therapeutic index. Option A reduces bioavailability, C reduces concentration, D may alter
absorption but not as directly increase free fraction.
3. A drug is administered as a racemic mixture of two enantiomers. Enantiomer A is primarily responsible for the
desired therapeutic effect, while Enantiomer B is inactive but is metabolized to a toxic metabolite. Which
pharmacokinetic property would most influence the drug's safety profile?
A) Volume of distribution of the racemic mixture
B) Half-life of Enantiomer B
C) Bioavailability of the racemic mixture
D) Protein binding of Enantiomer A
Answer: B
Rationale: The half-life of Enantiomer B determines its accumulation and the rate of toxic metabolite formation.
While other options affect overall drug exposure, the safety profile is directly linked to the kinetics of the toxic
enantiomer.
4. A patient with chronic kidney disease (CKD) stage 4 is prescribed a drug that is primarily eliminated unchanged
by the kidneys. Which adjustment in dosing regimen is most appropriate to maintain therapeutic efficacy while
minimizing toxicity?
A) Increase dose and decrease dosing interval
B) Decrease dose and increase dosing interval
C) Increase dose and maintain same dosing interval
D) Decrease dose and decrease dosing interval
,Answer: B
Rationale: In CKD, reduced renal clearance prolongs the drug's half-life. To avoid accumulation, the dose should be
decreased and/or the dosing interval increased. Option B achieves both, reducing peak and trough concentrations.
Other options risk toxicity or subtherapeutic levels.
5. Two drugs, X and Y, are both competitive antagonists at the same receptor. Drug X has a pA2 value of 8.5, and
Drug Y has a pA2 value of 7.2. Which statement accurately compares their potency?
A) Drug X is more potent because it has a higher pA2, indicating a lower dissociation constant.
B) Drug Y is more potent because it has a lower pA2, indicating higher affinity.
C) Potency cannot be determined from pA2 values alone; efficacy must be considered.
D) Both drugs have equal potency because pA2 reflects the antagonist's affinity regardless of value.
Answer: A
Rationale: pA2 is the negative logarithm of the antagonist concentration that causes a 2-fold shift in the agonist
dose-response curve. A higher pA2 indicates higher affinity (lower Kd). Thus, Drug X is more potent. Option B is
incorrect because lower pA2 means lower affinity. Option C confuses potency with efficacy.
6. A drug displays zero-order elimination kinetics. Which of the following statements about its pharmacokinetic
behavior is correct?
A) The half-life remains constant regardless of dose.
B) The rate of elimination is proportional to the drug concentration.
C) A small increase in dose can lead to a disproportionate increase in steady-state concentration.
D) The drug is likely to have a long half-life and accumulate extensively.
Answer: C
Rationale: Zero-order elimination means a constant amount is eliminated per unit time, independent of
concentration. Thus, increasing dose can saturate elimination pathways, causing disproportionate rises in
concentration. Option A describes first-order kinetics. Option B is first-order. Option D is not necessarily true.
7. A drug is highly bound to plasma proteins (99%) and has a low extraction ratio. Which change would most
significantly increase the free drug concentration in plasma?
A) Decreased hepatic blood flow
B) Induction of hepatic metabolizing enzymes
C) Hypoalbuminemia
D) Increased glomerular filtration rate
Answer: C
Rationale: Hypoalbuminemia reduces protein binding sites, increasing the free fraction of highly bound drugs. For
low extraction ratio drugs, clearance is sensitive to protein binding. Options A and B affect clearance but not
directly free concentration. Option D increases renal clearance of free drug, possibly reducing concentration.
8. A patient is receiving a continuous intravenous infusion of a drug. The drug has a half-life of 4 hours and follows
first-order kinetics. Approximately how long will it take to reach 94% of steady-state concentration?
A) 8 hours
B) 12 hours
C) 16 hours
D) 20 hours
Answer: C
Rationale: Steady-state is reached after about 4-5 half-lives. 94% corresponds to 4 half-lives (since 1/2^4 = 1/16 =
6.25% remaining, so 93.75% achieved). 4 half-lives = 16 hours. Option A (2 half-lives) gives 75%, B (3) gives
,87.5%, D (5) gives 96.875%.
9. A drug exhibits a volume of distribution (Vd) of 500 L in a 70 kg patient. Which interpretation of this value is
most accurate?
A) The drug is primarily confined to the plasma compartment.
B) The drug is extensively distributed into tissues and may be sequestered.
C) The drug has poor bioavailability due to extensive first-pass metabolism.
D) The drug is highly protein bound, limiting its distribution.
Answer: B
Rationale: A Vd of 500 L far exceeds total body water (42 L), indicating extensive tissue distribution or binding.
Option A would have Vd ~3-5 L. Option C relates to bioavailability, not Vd. Option D would decrease Vd, not
increase it.
10. A drug is a weak acid with a pKa of 4.5. In the stomach (pH 2), what is the ratio of unionized to ionized drug?
A) 1:100
B) 100:1
C) 1:1
D) 316:1
Answer: D
Rationale: Using Henderson-Hasselbalch for weak acids: pH = pKa + log([A-]/[HA]). 2 = 4.5 + log([A-]/[HA]) =>
log([A-]/[HA]) = -2.5 => [A-]/[HA] = 10^-2.5 "H 0.00316. Thus [HA]/[A-] "H 316:1. Option B would be for pH 6.5.
11. A drug exhibits a volume of distribution (Vd) of 500 L and a clearance (CL) of 50 L/hr. If the drug follows
first-order kinetics and a loading dose of 1000 mg is administered intravenously, what is the approximate half-life
of the drug?
A) 5 hours
B) 7 hours
C) 10 hours
D) 14 hours
Answer: B
Rationale: Half-life (t1/2) = 0.693 * Vd / CL = 0.693 * = 6.93 hours, approximately 7 hours. Option A (5
hr) would result from miscalculating Vd/CL without 0.693; C (10 hr) from using CL/Vd incorrectly; D (14 hr) from
doubling the correct value.
12. A drug is administered as a continuous intravenous infusion at a rate of 10 mg/hr. The drug has a clearance of 2
L/hr and a volume of distribution of 20 L. Approximately how long will it take for the plasma concentration to
reach 90% of steady state?
A) 10 hours
B) 23 hours
C) 46 hours
D) 92 hours
Answer: B
Rationale: Time to reach 90% steady state is about 3.3 half-lives. Half-life = 0.693 * Vd/CL = 0.693 * 20/2 = 6.93
hr. 3.3 * 6.93 "H 23 hr. Option A (10 hr) is roughly 1.5 half-lives; C (46 hr) is about 6.6 half-lives; D (92 hr) is about
13 half-lives.
, 13. A patient with hepatic cirrhosis has reduced CYP450 enzyme activity. Which pharmacokinetic parameter is
most likely to be increased for a high-extraction-ratio drug that is normally extensively metabolized in the liver?
A) Bioavailability
B) Clearance
C) Volume of distribution
D) Protein binding
Answer: A
Rationale: For high-extraction drugs, reduced hepatic metabolism increases bioavailability due to decreased
first-pass effect. Clearance (B) would decrease, not increase. Volume of distribution (C) may be altered by changes
in protein binding but not directly increased. Protein binding (D) is not consistently increased in cirrhosis.
14. A drug follows a two-compartment model with rapid distribution. After an IV bolus, the plasma
concentration-time curve shows a steep initial decline followed by a slower log-linear phase. The slope of the
terminal phase is used to estimate which parameter?
A) Distribution half-life
B) Elimination half-life
C) Volume of the central compartment
D) Clearance
Answer: B
Rationale: In a two-compartment model, the terminal log-linear phase represents elimination, and its slope yields the
elimination half-life. Distribution half-life (A) is from the initial fast phase. Volume of central compartment (C) is
estimated from the initial concentration. Clearance (D) requires AUC, not just terminal slope.
15. A drug has a therapeutic index (TI) of 2. Which statement about dosing is most accurate?
A) The drug is safe and does not require monitoring.
B) The effective dose is half the lethal dose.
C) The drug has a narrow margin of safety, requiring careful titration.
D) The drug can be administered at twice the recommended dose without toxicity.
Answer: C
Rationale: A TI of 2 indicates that the toxic dose is only twice the effective dose, a narrow margin requiring careful
monitoring. Option A is false; narrow TI drugs require monitoring. Option B describes TI as TD50/ED50, not half.
Option D is incorrect because doubling dose may cause toxicity.
16. A drug is a weak acid with pKa = 4.4. In the stomach (pH = 1.4), what is the ratio of ionized to unionized drug?
A) 1:1000
B) 1:100
C) 100:1
D) 1000:1
Answer: A
Rationale: Using Henderson-Hasselbalch for weak acids: pH = pKa + log([A-]/[HA]). 1.4 = 4.4 + log([A-]/[HA]) !’
log([A-]/[HA]) = -3 !’ [A-]/[HA] = 1/1000. Thus ratio ionized:unionized = 1:1000. Options B, C, D miscalculate
the exponent.
17. A drug is 99% bound to plasma proteins. Which of the following changes would most significantly increase the
free drug concentration?
A) A 10% decrease in protein binding
B) A 10% increase in total drug concentration
Nursing (PDF) — 200 Questions
Section 1: Pharmacokinetics and Pharmacodynamics (Questions 1-20)
1. A drug follows first-order elimination kinetics and has a half-life of 6 hours. If a patient receives an intravenous
bolus dose of 500 mg, approximately how many milligrams remain in the body 18 hours after administration?
A) 125 mg
B) 62.5 mg
C) 31.25 mg
D) 250 mg
Answer: B
Rationale: First-order kinetics means half-life is constant. After 18 hours (3 half-lives), the amount remaining is 500
mg / 2^3 = 62.5 mg. Option A (125 mg) corresponds to 2 half-lives, C to 4 half-lives, D to 1 half-life.
2. A drug with a narrow therapeutic index is administered orally. Which of the following scenarios would most
likely result in a supratherapeutic concentration leading to toxicity?
A) Increased first-pass metabolism due to enzyme induction
B) Decreased protein binding leading to higher free fraction
C) Increased renal clearance due to diuretic use
D) Decreased gastric emptying time
Answer: B
Rationale: Decreased protein binding increases the free (active) drug concentration, potentially causing toxicity for
drugs with narrow therapeutic index. Option A reduces bioavailability, C reduces concentration, D may alter
absorption but not as directly increase free fraction.
3. A drug is administered as a racemic mixture of two enantiomers. Enantiomer A is primarily responsible for the
desired therapeutic effect, while Enantiomer B is inactive but is metabolized to a toxic metabolite. Which
pharmacokinetic property would most influence the drug's safety profile?
A) Volume of distribution of the racemic mixture
B) Half-life of Enantiomer B
C) Bioavailability of the racemic mixture
D) Protein binding of Enantiomer A
Answer: B
Rationale: The half-life of Enantiomer B determines its accumulation and the rate of toxic metabolite formation.
While other options affect overall drug exposure, the safety profile is directly linked to the kinetics of the toxic
enantiomer.
4. A patient with chronic kidney disease (CKD) stage 4 is prescribed a drug that is primarily eliminated unchanged
by the kidneys. Which adjustment in dosing regimen is most appropriate to maintain therapeutic efficacy while
minimizing toxicity?
A) Increase dose and decrease dosing interval
B) Decrease dose and increase dosing interval
C) Increase dose and maintain same dosing interval
D) Decrease dose and decrease dosing interval
,Answer: B
Rationale: In CKD, reduced renal clearance prolongs the drug's half-life. To avoid accumulation, the dose should be
decreased and/or the dosing interval increased. Option B achieves both, reducing peak and trough concentrations.
Other options risk toxicity or subtherapeutic levels.
5. Two drugs, X and Y, are both competitive antagonists at the same receptor. Drug X has a pA2 value of 8.5, and
Drug Y has a pA2 value of 7.2. Which statement accurately compares their potency?
A) Drug X is more potent because it has a higher pA2, indicating a lower dissociation constant.
B) Drug Y is more potent because it has a lower pA2, indicating higher affinity.
C) Potency cannot be determined from pA2 values alone; efficacy must be considered.
D) Both drugs have equal potency because pA2 reflects the antagonist's affinity regardless of value.
Answer: A
Rationale: pA2 is the negative logarithm of the antagonist concentration that causes a 2-fold shift in the agonist
dose-response curve. A higher pA2 indicates higher affinity (lower Kd). Thus, Drug X is more potent. Option B is
incorrect because lower pA2 means lower affinity. Option C confuses potency with efficacy.
6. A drug displays zero-order elimination kinetics. Which of the following statements about its pharmacokinetic
behavior is correct?
A) The half-life remains constant regardless of dose.
B) The rate of elimination is proportional to the drug concentration.
C) A small increase in dose can lead to a disproportionate increase in steady-state concentration.
D) The drug is likely to have a long half-life and accumulate extensively.
Answer: C
Rationale: Zero-order elimination means a constant amount is eliminated per unit time, independent of
concentration. Thus, increasing dose can saturate elimination pathways, causing disproportionate rises in
concentration. Option A describes first-order kinetics. Option B is first-order. Option D is not necessarily true.
7. A drug is highly bound to plasma proteins (99%) and has a low extraction ratio. Which change would most
significantly increase the free drug concentration in plasma?
A) Decreased hepatic blood flow
B) Induction of hepatic metabolizing enzymes
C) Hypoalbuminemia
D) Increased glomerular filtration rate
Answer: C
Rationale: Hypoalbuminemia reduces protein binding sites, increasing the free fraction of highly bound drugs. For
low extraction ratio drugs, clearance is sensitive to protein binding. Options A and B affect clearance but not
directly free concentration. Option D increases renal clearance of free drug, possibly reducing concentration.
8. A patient is receiving a continuous intravenous infusion of a drug. The drug has a half-life of 4 hours and follows
first-order kinetics. Approximately how long will it take to reach 94% of steady-state concentration?
A) 8 hours
B) 12 hours
C) 16 hours
D) 20 hours
Answer: C
Rationale: Steady-state is reached after about 4-5 half-lives. 94% corresponds to 4 half-lives (since 1/2^4 = 1/16 =
6.25% remaining, so 93.75% achieved). 4 half-lives = 16 hours. Option A (2 half-lives) gives 75%, B (3) gives
,87.5%, D (5) gives 96.875%.
9. A drug exhibits a volume of distribution (Vd) of 500 L in a 70 kg patient. Which interpretation of this value is
most accurate?
A) The drug is primarily confined to the plasma compartment.
B) The drug is extensively distributed into tissues and may be sequestered.
C) The drug has poor bioavailability due to extensive first-pass metabolism.
D) The drug is highly protein bound, limiting its distribution.
Answer: B
Rationale: A Vd of 500 L far exceeds total body water (42 L), indicating extensive tissue distribution or binding.
Option A would have Vd ~3-5 L. Option C relates to bioavailability, not Vd. Option D would decrease Vd, not
increase it.
10. A drug is a weak acid with a pKa of 4.5. In the stomach (pH 2), what is the ratio of unionized to ionized drug?
A) 1:100
B) 100:1
C) 1:1
D) 316:1
Answer: D
Rationale: Using Henderson-Hasselbalch for weak acids: pH = pKa + log([A-]/[HA]). 2 = 4.5 + log([A-]/[HA]) =>
log([A-]/[HA]) = -2.5 => [A-]/[HA] = 10^-2.5 "H 0.00316. Thus [HA]/[A-] "H 316:1. Option B would be for pH 6.5.
11. A drug exhibits a volume of distribution (Vd) of 500 L and a clearance (CL) of 50 L/hr. If the drug follows
first-order kinetics and a loading dose of 1000 mg is administered intravenously, what is the approximate half-life
of the drug?
A) 5 hours
B) 7 hours
C) 10 hours
D) 14 hours
Answer: B
Rationale: Half-life (t1/2) = 0.693 * Vd / CL = 0.693 * = 6.93 hours, approximately 7 hours. Option A (5
hr) would result from miscalculating Vd/CL without 0.693; C (10 hr) from using CL/Vd incorrectly; D (14 hr) from
doubling the correct value.
12. A drug is administered as a continuous intravenous infusion at a rate of 10 mg/hr. The drug has a clearance of 2
L/hr and a volume of distribution of 20 L. Approximately how long will it take for the plasma concentration to
reach 90% of steady state?
A) 10 hours
B) 23 hours
C) 46 hours
D) 92 hours
Answer: B
Rationale: Time to reach 90% steady state is about 3.3 half-lives. Half-life = 0.693 * Vd/CL = 0.693 * 20/2 = 6.93
hr. 3.3 * 6.93 "H 23 hr. Option A (10 hr) is roughly 1.5 half-lives; C (46 hr) is about 6.6 half-lives; D (92 hr) is about
13 half-lives.
, 13. A patient with hepatic cirrhosis has reduced CYP450 enzyme activity. Which pharmacokinetic parameter is
most likely to be increased for a high-extraction-ratio drug that is normally extensively metabolized in the liver?
A) Bioavailability
B) Clearance
C) Volume of distribution
D) Protein binding
Answer: A
Rationale: For high-extraction drugs, reduced hepatic metabolism increases bioavailability due to decreased
first-pass effect. Clearance (B) would decrease, not increase. Volume of distribution (C) may be altered by changes
in protein binding but not directly increased. Protein binding (D) is not consistently increased in cirrhosis.
14. A drug follows a two-compartment model with rapid distribution. After an IV bolus, the plasma
concentration-time curve shows a steep initial decline followed by a slower log-linear phase. The slope of the
terminal phase is used to estimate which parameter?
A) Distribution half-life
B) Elimination half-life
C) Volume of the central compartment
D) Clearance
Answer: B
Rationale: In a two-compartment model, the terminal log-linear phase represents elimination, and its slope yields the
elimination half-life. Distribution half-life (A) is from the initial fast phase. Volume of central compartment (C) is
estimated from the initial concentration. Clearance (D) requires AUC, not just terminal slope.
15. A drug has a therapeutic index (TI) of 2. Which statement about dosing is most accurate?
A) The drug is safe and does not require monitoring.
B) The effective dose is half the lethal dose.
C) The drug has a narrow margin of safety, requiring careful titration.
D) The drug can be administered at twice the recommended dose without toxicity.
Answer: C
Rationale: A TI of 2 indicates that the toxic dose is only twice the effective dose, a narrow margin requiring careful
monitoring. Option A is false; narrow TI drugs require monitoring. Option B describes TI as TD50/ED50, not half.
Option D is incorrect because doubling dose may cause toxicity.
16. A drug is a weak acid with pKa = 4.4. In the stomach (pH = 1.4), what is the ratio of ionized to unionized drug?
A) 1:1000
B) 1:100
C) 100:1
D) 1000:1
Answer: A
Rationale: Using Henderson-Hasselbalch for weak acids: pH = pKa + log([A-]/[HA]). 1.4 = 4.4 + log([A-]/[HA]) !’
log([A-]/[HA]) = -3 !’ [A-]/[HA] = 1/1000. Thus ratio ionized:unionized = 1:1000. Options B, C, D miscalculate
the exponent.
17. A drug is 99% bound to plasma proteins. Which of the following changes would most significantly increase the
free drug concentration?
A) A 10% decrease in protein binding
B) A 10% increase in total drug concentration
