HESI Pharmacology Exam Practice – Comprehensive
Study Guide & Practice Questions | Nursing
Pharmacology Review, Medication Safety & Exam
Preparation
Section 1: Pharmacokinetics & Pharmacodynamics (Questions 1–20)
1. A nurse is preparing to administer a medication that follows first-order
kinetics. Which statement best describes the elimination of this drug?
A. A constant amount of drug is eliminated per unit of time, regardless of plasma
concentration.
B. A constant percentage of the drug is eliminated per unit of time, proportional
to plasma concentration.
C. The drug is eliminated only after reaching a steady-state concentration.
D. Elimination occurs via zero-order pathways once the drug saturates liver
enzymes.
Correct Answer: B
Rationale: First-order kinetics (linear kinetics) means that a constant
percentage of the drug is eliminated per unit of time. The rate of elimination is
directly proportional to the plasma concentration. This is the most common type
of drug elimination. Option A describes zero-order kinetics (e.g., ethanol,
phenytoin at high doses). Option D is a distractor describing saturation kinetics.
2. Which of the following factors would most likely decrease the bioavailability
of an orally administered drug?
A. Taking the medication with a full glass of water.
B. Extensive first-pass metabolism in the liver.
C. Administering the drug on an empty stomach.
D. Using a liquid formulation instead of a tablet.
Correct Answer: B
Rationale: First-pass metabolism refers to the metabolism of a drug in the
liver and gut wall before it reaches systemic circulation. A drug with extensive
,first-pass metabolism will have reduced bioavailability when given orally. Taking
with water (A) generally aids absorption. Empty stomach (C) may increase or
decrease absorption depending on the drug but doesn't inherently reduce
bioavailability like first-pass does. Liquid formulations (D) typically have higher
bioavailability.
3. A nurse is reviewing the mechanism of action of a new medication. The drug
binds to a receptor and produces a maximal response. This drug is best classified
as a:
A. Partial agonist.
B. Competitive antagonist.
C. Full agonist.
D. Noncompetitive antagonist.
Correct Answer: C
Rationale: A full agonist binds to a receptor and produces a maximal
biological response. A partial agonist (A) produces a submaximal response even at
full receptor occupancy. A competitive antagonist (B) blocks the agonist's effect
by competing for the same binding site. A noncompetitive antagonist (D) binds at
an allosteric site and reduces the maximal response.
4. Which of the following is a primary site of drug metabolism?
A. Kidneys.
B. Lungs.
C. Liver.
D. Plasma.
Correct Answer: C
Rationale: The liver is the primary organ for drug metabolism, primarily via
the cytochrome P450 enzyme system. The kidneys (A) are the primary route of
drug excretion. The lungs (B) and plasma (D) can metabolize certain drugs, but the
liver is the major site.
5. A client is taking a drug with a narrow therapeutic index. What is the most
important nursing implication?
,A. The drug is safe for use during pregnancy.
B. Small changes in dose or metabolism can lead to toxicity or therapeutic failure.
C. The drug can be administered without regard to food intake.
D. The drug is unlikely to interact with other medications.
Correct Answer: B
Rationale: A narrow therapeutic index means the difference between the
therapeutic dose and the toxic dose is small. Therefore, small changes in dose,
absorption, or metabolism can lead to toxicity or therapeutic failure. Clients on
these drugs (e.g., digoxin, warfarin, phenytoin) require close monitoring.
6. Which of the following routes of administration provides the most rapid
onset of action?
A. Oral.
B. Subcutaneous.
C. Intramuscular.
D. Intravenous.
Correct Answer: D
Rationale: Intravenous (IV) administration bypasses the absorption phase
entirely, delivering the drug directly into systemic circulation. This provides the
most rapid onset of action. Oral (A) is the slowest, while subcutaneous (B) and
intramuscular (C) are intermediate, depending on blood flow to the site.
7. A nurse is administering a drug that is highly protein-bound. What is the
primary clinical concern?
A. The drug will be rapidly excreted by the kidneys.
B. Only the unbound (free) fraction of the drug is pharmacologically active.
C. The drug will have a very short half-life.
D. The drug will not cross the blood-brain barrier.
Correct Answer: B
Rationale: Only the unbound (free) fraction of a drug is pharmacologically
active and able to cross membranes to reach target tissues. If a drug is highly
, protein-bound (e.g., warfarin), it can be displaced by other protein-bound drugs,
increasing the free fraction and potentially causing toxicity.
8. A client asks how a medication "knows" to go to the heart. The nurse explains
that drug selectivity is primarily determined by:
A. The route of administration.
B. The pH of the stomach.
C. The binding affinity to specific receptors.
D. The rate of renal excretion.
Correct Answer: C
Rationale: Drug selectivity is largely determined by the drug's binding
affinity to specific receptors located in target tissues. A drug that binds only to
beta-1 receptors will primarily affect the heart, whereas a nonselective beta-
blocker affects both beta-1 and beta-2 receptors.
9. Which of the following is an example of a drug that follows zero-order
kinetics?
A. Aspirin.
B. Penicillin.
C. Phenytoin at high doses.
D. Metformin.
Correct Answer: C
Rationale: Zero-order kinetics occurs when the elimination pathways are
saturated, so a constant amount of drug is eliminated per unit of time regardless
of concentration. Phenytoin exhibits zero-order kinetics at high therapeutic doses.
Aspirin (A) and penicillin (B) follow first-order kinetics. Metformin (D) is
eliminated unchanged by the kidneys (first-order).
10. A nurse is teaching a client about a medication that is a substrate of CYP3A4.
Which substance should the client avoid due to potential drug interaction?
A. Orange juice.
B. Grapefruit juice.
Study Guide & Practice Questions | Nursing
Pharmacology Review, Medication Safety & Exam
Preparation
Section 1: Pharmacokinetics & Pharmacodynamics (Questions 1–20)
1. A nurse is preparing to administer a medication that follows first-order
kinetics. Which statement best describes the elimination of this drug?
A. A constant amount of drug is eliminated per unit of time, regardless of plasma
concentration.
B. A constant percentage of the drug is eliminated per unit of time, proportional
to plasma concentration.
C. The drug is eliminated only after reaching a steady-state concentration.
D. Elimination occurs via zero-order pathways once the drug saturates liver
enzymes.
Correct Answer: B
Rationale: First-order kinetics (linear kinetics) means that a constant
percentage of the drug is eliminated per unit of time. The rate of elimination is
directly proportional to the plasma concentration. This is the most common type
of drug elimination. Option A describes zero-order kinetics (e.g., ethanol,
phenytoin at high doses). Option D is a distractor describing saturation kinetics.
2. Which of the following factors would most likely decrease the bioavailability
of an orally administered drug?
A. Taking the medication with a full glass of water.
B. Extensive first-pass metabolism in the liver.
C. Administering the drug on an empty stomach.
D. Using a liquid formulation instead of a tablet.
Correct Answer: B
Rationale: First-pass metabolism refers to the metabolism of a drug in the
liver and gut wall before it reaches systemic circulation. A drug with extensive
,first-pass metabolism will have reduced bioavailability when given orally. Taking
with water (A) generally aids absorption. Empty stomach (C) may increase or
decrease absorption depending on the drug but doesn't inherently reduce
bioavailability like first-pass does. Liquid formulations (D) typically have higher
bioavailability.
3. A nurse is reviewing the mechanism of action of a new medication. The drug
binds to a receptor and produces a maximal response. This drug is best classified
as a:
A. Partial agonist.
B. Competitive antagonist.
C. Full agonist.
D. Noncompetitive antagonist.
Correct Answer: C
Rationale: A full agonist binds to a receptor and produces a maximal
biological response. A partial agonist (A) produces a submaximal response even at
full receptor occupancy. A competitive antagonist (B) blocks the agonist's effect
by competing for the same binding site. A noncompetitive antagonist (D) binds at
an allosteric site and reduces the maximal response.
4. Which of the following is a primary site of drug metabolism?
A. Kidneys.
B. Lungs.
C. Liver.
D. Plasma.
Correct Answer: C
Rationale: The liver is the primary organ for drug metabolism, primarily via
the cytochrome P450 enzyme system. The kidneys (A) are the primary route of
drug excretion. The lungs (B) and plasma (D) can metabolize certain drugs, but the
liver is the major site.
5. A client is taking a drug with a narrow therapeutic index. What is the most
important nursing implication?
,A. The drug is safe for use during pregnancy.
B. Small changes in dose or metabolism can lead to toxicity or therapeutic failure.
C. The drug can be administered without regard to food intake.
D. The drug is unlikely to interact with other medications.
Correct Answer: B
Rationale: A narrow therapeutic index means the difference between the
therapeutic dose and the toxic dose is small. Therefore, small changes in dose,
absorption, or metabolism can lead to toxicity or therapeutic failure. Clients on
these drugs (e.g., digoxin, warfarin, phenytoin) require close monitoring.
6. Which of the following routes of administration provides the most rapid
onset of action?
A. Oral.
B. Subcutaneous.
C. Intramuscular.
D. Intravenous.
Correct Answer: D
Rationale: Intravenous (IV) administration bypasses the absorption phase
entirely, delivering the drug directly into systemic circulation. This provides the
most rapid onset of action. Oral (A) is the slowest, while subcutaneous (B) and
intramuscular (C) are intermediate, depending on blood flow to the site.
7. A nurse is administering a drug that is highly protein-bound. What is the
primary clinical concern?
A. The drug will be rapidly excreted by the kidneys.
B. Only the unbound (free) fraction of the drug is pharmacologically active.
C. The drug will have a very short half-life.
D. The drug will not cross the blood-brain barrier.
Correct Answer: B
Rationale: Only the unbound (free) fraction of a drug is pharmacologically
active and able to cross membranes to reach target tissues. If a drug is highly
, protein-bound (e.g., warfarin), it can be displaced by other protein-bound drugs,
increasing the free fraction and potentially causing toxicity.
8. A client asks how a medication "knows" to go to the heart. The nurse explains
that drug selectivity is primarily determined by:
A. The route of administration.
B. The pH of the stomach.
C. The binding affinity to specific receptors.
D. The rate of renal excretion.
Correct Answer: C
Rationale: Drug selectivity is largely determined by the drug's binding
affinity to specific receptors located in target tissues. A drug that binds only to
beta-1 receptors will primarily affect the heart, whereas a nonselective beta-
blocker affects both beta-1 and beta-2 receptors.
9. Which of the following is an example of a drug that follows zero-order
kinetics?
A. Aspirin.
B. Penicillin.
C. Phenytoin at high doses.
D. Metformin.
Correct Answer: C
Rationale: Zero-order kinetics occurs when the elimination pathways are
saturated, so a constant amount of drug is eliminated per unit of time regardless
of concentration. Phenytoin exhibits zero-order kinetics at high therapeutic doses.
Aspirin (A) and penicillin (B) follow first-order kinetics. Metformin (D) is
eliminated unchanged by the kidneys (first-order).
10. A nurse is teaching a client about a medication that is a substrate of CYP3A4.
Which substance should the client avoid due to potential drug interaction?
A. Orange juice.
B. Grapefruit juice.
