Test Bank for Basic and Clinical Pharmacology
(15th Edition) by Katzung & Trevor - Graded
A+ Comprehensive Exam ...
SECTION I: BASIC PRINCIPLES
1. A nurse working in radiology administers iodine to a patient who is having a
computed tomography (CT) scan. The nurse working on the oncology unit
administers chemotherapy to patients who have cancer. At the Public Health
Department, a nurse administers a measles-mumps-rubella (MMR) vaccine to a
14-month-old child as a routine immunization. Which branch of pharmacology
best describes the actions of all three nurses?
A) Pharmacoeconomics
B) Pharmacotherapeutics
C) Pharmacodynamics
D) Pharmacokinetics
Correct Answer: B
Rationale: Pharmacotherapeutics is the branch of pharmacology that
considers the therapeutic uses and effects of drugs—including diagnostic agents
(iodine for CT), chemotherapeutic agents (cancer treatment), and immunizing
agents (vaccines). Pharmacoeconomics examines the cost-effectiveness of drug
therapy. Pharmacodynamics describes what the drug does to the body (receptor
interactions, mechanism of action). Pharmacokinetics describes what the body
does to the drug (absorption, distribution, metabolism, excretion).
2. A 16-year-old girl suffering from seasonal rhinitis started therapy with a
medication. Which term best describes the intrinsic ability of a drug to bind with
receptors?
A) Intrinsic activity
B) Affinity
,C) Efficacy
D) Potency
Correct Answer: B
Rationale: Affinity refers to the strength of the drug–receptor binding
interaction—the tendency of a drug to bind to its receptor. Intrinsic activity
(efficacy) is the ability of a bound drug to activate the receptor and produce a
response. Potency refers to the concentration of drug required to produce 50% of
maximal effect (EC₅₀). A drug can have high affinity but zero intrinsic activity
(antagonist).
3. Which of the following statements best distinguishes a full agonist from a
partial agonist?
A) A full agonist has higher affinity than a partial agonist.
B) A partial agonist produces a lower maximal response than a full agonist even at
full receptor occupancy.
C) A full agonist binds to a different receptor site than a partial agonist.
D) A partial agonist is always less potent than a full agonist.
Correct Answer: B
Rationale: The defining characteristic of a partial agonist is that it
produces a submaximal response even when occupying all available receptors.
This is due to lower intrinsic activity (efficacy). Affinity may be equal or even
higher for a partial agonist. Potency (EC₅₀) is independent of efficacy; a partial
agonist can be more potent (lower EC₅₀) than a full agonist while still producing a
smaller maximal response.
4. A competitive antagonist shifts the dose–response curve of an agonist to the:
A) Right, with a decrease in maximal efficacy
B) Right, with no change in maximal efficacy
C) Left, with an increase in maximal efficacy
D) Left, with no change in maximal efficacy
, Correct Answer: B
Rationale: Competitive (reversible) antagonists bind reversibly to the
same receptor site as the agonist. They shift the agonist dose–response curve to
the right in a parallel fashion without reducing the maximal response, because the
block can be overcome by increasing the agonist concentration. Noncompetitive
(irreversible) antagonists reduce maximal efficacy.
5. Which of the following is a correct statement regarding the therapeutic index
(TI) of a drug?
A) A higher TI indicates a greater margin of safety.
B) A lower TI indicates a greater margin of safety.
C) TI is calculated as ED₅₀/LD₅₀.
D) TI is independent of drug potency.
Correct Answer: A
Rationale: The therapeutic index is the ratio of the median toxic dose
(TD₅₀) or lethal dose (LD₅₀) to the median effective dose (ED₅₀). A higher TI means
a larger separation between therapeutic and toxic doses, indicating a greater
margin of safety. A lower TI (e.g., digoxin, lithium, warfarin) requires careful
monitoring.
6. Which of the following signaling mechanisms has the most rapid onset of
action?
A) Ligand-gated ion channel
B) G protein-coupled receptor
C) Receptor tyrosine kinase
D) Nuclear receptor
Correct Answer: A
Rationale: Ligand-gated ion channels (ionotropic receptors) mediate the
fastest signaling events—on the order of milliseconds—because receptor
, activation directly opens an ion channel, allowing immediate ion flux and changes
in membrane potential. G protein-coupled receptors act within seconds to
minutes; receptor tyrosine kinases act over minutes to hours; nuclear receptors
alter gene transcription and act over hours to days.
7. A drug that is eliminated by first-order kinetics:
A) Eliminates a constant amount of drug per unit time
B) Has a half-life that increases as plasma concentration increases
C) Eliminates a constant fraction of drug per unit time
D) Shows zero-order elimination at therapeutic doses
Correct Answer: C
Rationale: First-order (linear) kinetics means that a constant fraction
(proportion) of the drug is eliminated per unit time. The half-life is constant
regardless of plasma concentration. Zero-order (capacity-limited, nonlinear)
kinetics eliminates a constant amount per unit time (e.g., ethanol, phenytoin at
high doses, aspirin at high doses).
8. Which of the following pharmacokinetic parameters describes the apparent
volume of fluid from which a drug is distributed?
A) Clearance
B) Volume of distribution (Vd)
C) Bioavailability
D) Half-life
Correct Answer: B
Rationale: Volume of distribution (Vd) is the theoretical volume into which
the total amount of drug in the body would need to be distributed to produce the
observed plasma concentration (Vd = amount of drug in body / plasma
concentration). A large Vd indicates extensive tissue distribution. Clearance
describes the volume of plasma cleared of drug per unit time. Bioavailability is the
(15th Edition) by Katzung & Trevor - Graded
A+ Comprehensive Exam ...
SECTION I: BASIC PRINCIPLES
1. A nurse working in radiology administers iodine to a patient who is having a
computed tomography (CT) scan. The nurse working on the oncology unit
administers chemotherapy to patients who have cancer. At the Public Health
Department, a nurse administers a measles-mumps-rubella (MMR) vaccine to a
14-month-old child as a routine immunization. Which branch of pharmacology
best describes the actions of all three nurses?
A) Pharmacoeconomics
B) Pharmacotherapeutics
C) Pharmacodynamics
D) Pharmacokinetics
Correct Answer: B
Rationale: Pharmacotherapeutics is the branch of pharmacology that
considers the therapeutic uses and effects of drugs—including diagnostic agents
(iodine for CT), chemotherapeutic agents (cancer treatment), and immunizing
agents (vaccines). Pharmacoeconomics examines the cost-effectiveness of drug
therapy. Pharmacodynamics describes what the drug does to the body (receptor
interactions, mechanism of action). Pharmacokinetics describes what the body
does to the drug (absorption, distribution, metabolism, excretion).
2. A 16-year-old girl suffering from seasonal rhinitis started therapy with a
medication. Which term best describes the intrinsic ability of a drug to bind with
receptors?
A) Intrinsic activity
B) Affinity
,C) Efficacy
D) Potency
Correct Answer: B
Rationale: Affinity refers to the strength of the drug–receptor binding
interaction—the tendency of a drug to bind to its receptor. Intrinsic activity
(efficacy) is the ability of a bound drug to activate the receptor and produce a
response. Potency refers to the concentration of drug required to produce 50% of
maximal effect (EC₅₀). A drug can have high affinity but zero intrinsic activity
(antagonist).
3. Which of the following statements best distinguishes a full agonist from a
partial agonist?
A) A full agonist has higher affinity than a partial agonist.
B) A partial agonist produces a lower maximal response than a full agonist even at
full receptor occupancy.
C) A full agonist binds to a different receptor site than a partial agonist.
D) A partial agonist is always less potent than a full agonist.
Correct Answer: B
Rationale: The defining characteristic of a partial agonist is that it
produces a submaximal response even when occupying all available receptors.
This is due to lower intrinsic activity (efficacy). Affinity may be equal or even
higher for a partial agonist. Potency (EC₅₀) is independent of efficacy; a partial
agonist can be more potent (lower EC₅₀) than a full agonist while still producing a
smaller maximal response.
4. A competitive antagonist shifts the dose–response curve of an agonist to the:
A) Right, with a decrease in maximal efficacy
B) Right, with no change in maximal efficacy
C) Left, with an increase in maximal efficacy
D) Left, with no change in maximal efficacy
, Correct Answer: B
Rationale: Competitive (reversible) antagonists bind reversibly to the
same receptor site as the agonist. They shift the agonist dose–response curve to
the right in a parallel fashion without reducing the maximal response, because the
block can be overcome by increasing the agonist concentration. Noncompetitive
(irreversible) antagonists reduce maximal efficacy.
5. Which of the following is a correct statement regarding the therapeutic index
(TI) of a drug?
A) A higher TI indicates a greater margin of safety.
B) A lower TI indicates a greater margin of safety.
C) TI is calculated as ED₅₀/LD₅₀.
D) TI is independent of drug potency.
Correct Answer: A
Rationale: The therapeutic index is the ratio of the median toxic dose
(TD₅₀) or lethal dose (LD₅₀) to the median effective dose (ED₅₀). A higher TI means
a larger separation between therapeutic and toxic doses, indicating a greater
margin of safety. A lower TI (e.g., digoxin, lithium, warfarin) requires careful
monitoring.
6. Which of the following signaling mechanisms has the most rapid onset of
action?
A) Ligand-gated ion channel
B) G protein-coupled receptor
C) Receptor tyrosine kinase
D) Nuclear receptor
Correct Answer: A
Rationale: Ligand-gated ion channels (ionotropic receptors) mediate the
fastest signaling events—on the order of milliseconds—because receptor
, activation directly opens an ion channel, allowing immediate ion flux and changes
in membrane potential. G protein-coupled receptors act within seconds to
minutes; receptor tyrosine kinases act over minutes to hours; nuclear receptors
alter gene transcription and act over hours to days.
7. A drug that is eliminated by first-order kinetics:
A) Eliminates a constant amount of drug per unit time
B) Has a half-life that increases as plasma concentration increases
C) Eliminates a constant fraction of drug per unit time
D) Shows zero-order elimination at therapeutic doses
Correct Answer: C
Rationale: First-order (linear) kinetics means that a constant fraction
(proportion) of the drug is eliminated per unit time. The half-life is constant
regardless of plasma concentration. Zero-order (capacity-limited, nonlinear)
kinetics eliminates a constant amount per unit time (e.g., ethanol, phenytoin at
high doses, aspirin at high doses).
8. Which of the following pharmacokinetic parameters describes the apparent
volume of fluid from which a drug is distributed?
A) Clearance
B) Volume of distribution (Vd)
C) Bioavailability
D) Half-life
Correct Answer: B
Rationale: Volume of distribution (Vd) is the theoretical volume into which
the total amount of drug in the body would need to be distributed to produce the
observed plasma concentration (Vd = amount of drug in body / plasma
concentration). A large Vd indicates extensive tissue distribution. Clearance
describes the volume of plasma cleared of drug per unit time. Bioavailability is the
