Comprehensive Pharmacology Board
Review Test (2026 Edition)|| Questions
And Answers With Rationales/Graded
A+/2026 Update/100% Correct
/Instant Download
Total Questions: 85
Format: Multiple Choice
Instructions: Select the single best answer. Correct answers are highlighted in
bold. A rationale follows each question.
Section 1: General Principles (Questions 1–12)
1. A drug that binds to a receptor and produces a maximal biological response
is a:
a) Antagonist
b) Partial agonist
c) Inverse agonist
d) Full agonist
*Rationale: Full agonists have high intrinsic activity (efficacy = 1), producing
maximal effect upon receptor occupancy.*
2. Which phase of drug metabolism involves conjugation reactions such as
glucuronidation?
a) Phase I
b) Phase II
c) Phase 0
d) Phase III
Rationale: Phase II reactions add endogenous groups (e.g., glucuronic acid,
sulfate) to increase water solubility and excretion.
3. A drug with a volume of distribution (Vd) of 40 L in a 70 kg adult suggests:
a) Confined to plasma
,b) Confined to extracellular fluid
c) Distributed throughout total body water
d) Sequestered in fat tissue
Rationale: Total body water is ~42 L; Vd 40 L indicates distribution into
intracellular and extracellular fluid.
4. Which of the following is an irreversible antagonist?
a) Metoprolol
b) Naloxone
c) Phenoxybenzamine
d) Atropine
Rationale: Phenoxybenzamine covalently binds to α-adrenoceptors, producing
long-lasting, irreversible blockade.
5. The therapeutic index (TI) is defined as:
a) ED50/TD50
b) TD99/ED1
c) TD50/ED50
d) ED50/ED99
*Rationale: TI = median toxic dose (TD50) / median effective dose (ED50).
Higher TI indicates safer drug.*
6. Zero-order kinetics is characterized by:
a) Constant half-life
b) First-order elimination rate
c) Constant amount of drug eliminated per unit time
d) Proportionality between concentration and elimination rate
Rationale: Zero-order elimination (e.g., phenytoin, ethanol) saturates metabolic
pathways, so rate is constant.
7. The primary site of drug metabolism is:
a) Kidney
b) Liver
c) Lungs
d) Intestinal lumen
Rationale: Liver contains cytochrome P450 enzymes and conjugation systems.
8. A weak acid drug (pKa = 4.4) is placed in the stomach (pH 1.4). What is its
ionization state?
a) Mostly non-ionized
, b) Mostly ionized
c) 50% ionized
d) Completely ionized
*Rationale: For weak acid, pH – pKa = –3 → non-ionized form predominates,
favoring absorption.*
9. Enterohepatic recirculation leads to:
a) Shorter duration of action
b) Prolonged drug effect
c) Decreased half-life
d) Reduced bioavailability
Rationale: Drug excreted in bile is reabsorbed in intestine, prolonging presence in
body.
10. The CYP450 isoenzyme responsible for metabolism of warfarin,
phenytoin, and many statins is:
a) CYP2D6
b) CYP3A4
c) CYP2C9
d) CYP1A2
*Rationale: CYP2C9 metabolizes warfarin (S-enantiomer), phenytoin, and some
NSAIDs.*
11. Grapefruit juice increases drug levels of oral felodipine by inhibiting:
a) CYP2D6
b) CYP3A4 (intestinal)
c) CYP2C19
d) P-glycoprotein only
Rationale: Grapefruit juice inhibits intestinal CYP3A4, increasing bioavailability
of many calcium channel blockers.
12. Which parameter is most useful for determining a dosing interval?
a) Volume of distribution
b) Elimination half-life
c) Bioavailability
d) Protein binding
*Rationale: Half-life determines time to reach steady state and dosing frequency
(usually 1 half-life interval).*
Review Test (2026 Edition)|| Questions
And Answers With Rationales/Graded
A+/2026 Update/100% Correct
/Instant Download
Total Questions: 85
Format: Multiple Choice
Instructions: Select the single best answer. Correct answers are highlighted in
bold. A rationale follows each question.
Section 1: General Principles (Questions 1–12)
1. A drug that binds to a receptor and produces a maximal biological response
is a:
a) Antagonist
b) Partial agonist
c) Inverse agonist
d) Full agonist
*Rationale: Full agonists have high intrinsic activity (efficacy = 1), producing
maximal effect upon receptor occupancy.*
2. Which phase of drug metabolism involves conjugation reactions such as
glucuronidation?
a) Phase I
b) Phase II
c) Phase 0
d) Phase III
Rationale: Phase II reactions add endogenous groups (e.g., glucuronic acid,
sulfate) to increase water solubility and excretion.
3. A drug with a volume of distribution (Vd) of 40 L in a 70 kg adult suggests:
a) Confined to plasma
,b) Confined to extracellular fluid
c) Distributed throughout total body water
d) Sequestered in fat tissue
Rationale: Total body water is ~42 L; Vd 40 L indicates distribution into
intracellular and extracellular fluid.
4. Which of the following is an irreversible antagonist?
a) Metoprolol
b) Naloxone
c) Phenoxybenzamine
d) Atropine
Rationale: Phenoxybenzamine covalently binds to α-adrenoceptors, producing
long-lasting, irreversible blockade.
5. The therapeutic index (TI) is defined as:
a) ED50/TD50
b) TD99/ED1
c) TD50/ED50
d) ED50/ED99
*Rationale: TI = median toxic dose (TD50) / median effective dose (ED50).
Higher TI indicates safer drug.*
6. Zero-order kinetics is characterized by:
a) Constant half-life
b) First-order elimination rate
c) Constant amount of drug eliminated per unit time
d) Proportionality between concentration and elimination rate
Rationale: Zero-order elimination (e.g., phenytoin, ethanol) saturates metabolic
pathways, so rate is constant.
7. The primary site of drug metabolism is:
a) Kidney
b) Liver
c) Lungs
d) Intestinal lumen
Rationale: Liver contains cytochrome P450 enzymes and conjugation systems.
8. A weak acid drug (pKa = 4.4) is placed in the stomach (pH 1.4). What is its
ionization state?
a) Mostly non-ionized
, b) Mostly ionized
c) 50% ionized
d) Completely ionized
*Rationale: For weak acid, pH – pKa = –3 → non-ionized form predominates,
favoring absorption.*
9. Enterohepatic recirculation leads to:
a) Shorter duration of action
b) Prolonged drug effect
c) Decreased half-life
d) Reduced bioavailability
Rationale: Drug excreted in bile is reabsorbed in intestine, prolonging presence in
body.
10. The CYP450 isoenzyme responsible for metabolism of warfarin,
phenytoin, and many statins is:
a) CYP2D6
b) CYP3A4
c) CYP2C9
d) CYP1A2
*Rationale: CYP2C9 metabolizes warfarin (S-enantiomer), phenytoin, and some
NSAIDs.*
11. Grapefruit juice increases drug levels of oral felodipine by inhibiting:
a) CYP2D6
b) CYP3A4 (intestinal)
c) CYP2C19
d) P-glycoprotein only
Rationale: Grapefruit juice inhibits intestinal CYP3A4, increasing bioavailability
of many calcium channel blockers.
12. Which parameter is most useful for determining a dosing interval?
a) Volume of distribution
b) Elimination half-life
c) Bioavailability
d) Protein binding
*Rationale: Half-life determines time to reach steady state and dosing frequency
(usually 1 half-life interval).*
