PHARMACOLOGY EXAM
TOOLKIT: TOPIC TEST
2026||Questions And Answers With
Rationales/Graded A+/2026
Update/100% Correct /Instant
Download
Total Questions: 85
Time Allowed: 100 minutes
Instructions: Select the single best answer for each question. Highlighted bold
option indicates the correct answer.
SECTION A: PHARMACOKINETICS & PHARMACODYNAMICS (Qs 1-
15)
1. A drug with zero-order kinetics:
• A) Eliminates at a rate proportional to drug concentration
• B) Eliminates a constant amount per unit time
• C) Has a constant half-life regardless of dose
• D) Is best represented by first-order exponential decay
Rationale: Zero-order kinetics means a fixed amount of drug is eliminated per
time (e.g., phenytoin, ethanol). Half-life changes with dose.
2. Which factor most increases the volume of distribution (Vd) of a lipophilic
drug?
• A) High tissue binding and low plasma protein binding
• B) Low tissue binding and high plasma protein binding
• C) High molecular weight and ionization at pH 7.4
, • D) Exclusive distribution to extracellular fluid
Rationale: Lipophilic drugs with high tissue affinity (e.g., digoxin) have large Vd.
High plasma protein binding decreases Vd.
3. Bioavailability of an intravenous drug is always:
• A) <100% due to first-pass metabolism
• B) 100% by definition
• C) Dependent on gastric emptying time
• D) Reduced by CYP450 inducers
Rationale: IV administration bypasses absorption barriers, so bioavailability =
100%.
4. A drug with a therapeutic index (TI) of 2 is considered:
• A) Very safe
• B) Narrow therapeutic window, high risk
• C) Ideal for OTC use
• D) TI irrelevant to safety
Rationale: TI = TD50/ED50. TI < 3 indicates narrow margin between efficacy and
toxicity (e.g., warfarin, lithium).
5. Which process is primarily responsible for drug absorption from the small
intestine?
• A) Active transport only
• B) Paracellular diffusion only
• C) Passive diffusion of non-ionized, lipophilic forms
• D) Endocytosis of protein-bound drugs
Rationale: Most drugs are absorbed via passive diffusion. The Henderson-
Hasselbalch principle applies.
6. First-pass metabolism reduces oral bioavailability of which drug most
significantly?
, • A) Digoxin
• B) Propranolol
• C) Vancomycin
• D) Heparin
Rationale: Propranolol undergoes extensive hepatic first-pass metabolism (~75%
lost). Heparin is not absorbed orally.
7. The half-life (t½) of a drug is 4 hours. Approximately how long to reach
steady state?
• A) 8 hours
• B) 12 hours
• C) 20 hours (5 × t½)
• D) 40 hours
Rationale: Steady state is achieved in 4-5 half-lives. 5 × 4 = 20 hours.
8. Which CYP450 isoenzyme is most commonly involved in clinically
significant drug interactions?
• A) CYP1A2
• B) CYP3A4
• C) CYP2D6
• D) CYP2E1
Rationale: CYP3A4 metabolizes >50% of drugs (e.g., statins, benzodiazepines,
calcium channel blockers).
9. A weak acid (pKa 4.5) will be mostly _____ in gastric fluid (pH 1.5).
• A) Non-ionized, favoring absorption
• B) Ionized, favoring excretion
• C) Trapped in stomach
• D) Precipitated
TOOLKIT: TOPIC TEST
2026||Questions And Answers With
Rationales/Graded A+/2026
Update/100% Correct /Instant
Download
Total Questions: 85
Time Allowed: 100 minutes
Instructions: Select the single best answer for each question. Highlighted bold
option indicates the correct answer.
SECTION A: PHARMACOKINETICS & PHARMACODYNAMICS (Qs 1-
15)
1. A drug with zero-order kinetics:
• A) Eliminates at a rate proportional to drug concentration
• B) Eliminates a constant amount per unit time
• C) Has a constant half-life regardless of dose
• D) Is best represented by first-order exponential decay
Rationale: Zero-order kinetics means a fixed amount of drug is eliminated per
time (e.g., phenytoin, ethanol). Half-life changes with dose.
2. Which factor most increases the volume of distribution (Vd) of a lipophilic
drug?
• A) High tissue binding and low plasma protein binding
• B) Low tissue binding and high plasma protein binding
• C) High molecular weight and ionization at pH 7.4
, • D) Exclusive distribution to extracellular fluid
Rationale: Lipophilic drugs with high tissue affinity (e.g., digoxin) have large Vd.
High plasma protein binding decreases Vd.
3. Bioavailability of an intravenous drug is always:
• A) <100% due to first-pass metabolism
• B) 100% by definition
• C) Dependent on gastric emptying time
• D) Reduced by CYP450 inducers
Rationale: IV administration bypasses absorption barriers, so bioavailability =
100%.
4. A drug with a therapeutic index (TI) of 2 is considered:
• A) Very safe
• B) Narrow therapeutic window, high risk
• C) Ideal for OTC use
• D) TI irrelevant to safety
Rationale: TI = TD50/ED50. TI < 3 indicates narrow margin between efficacy and
toxicity (e.g., warfarin, lithium).
5. Which process is primarily responsible for drug absorption from the small
intestine?
• A) Active transport only
• B) Paracellular diffusion only
• C) Passive diffusion of non-ionized, lipophilic forms
• D) Endocytosis of protein-bound drugs
Rationale: Most drugs are absorbed via passive diffusion. The Henderson-
Hasselbalch principle applies.
6. First-pass metabolism reduces oral bioavailability of which drug most
significantly?
, • A) Digoxin
• B) Propranolol
• C) Vancomycin
• D) Heparin
Rationale: Propranolol undergoes extensive hepatic first-pass metabolism (~75%
lost). Heparin is not absorbed orally.
7. The half-life (t½) of a drug is 4 hours. Approximately how long to reach
steady state?
• A) 8 hours
• B) 12 hours
• C) 20 hours (5 × t½)
• D) 40 hours
Rationale: Steady state is achieved in 4-5 half-lives. 5 × 4 = 20 hours.
8. Which CYP450 isoenzyme is most commonly involved in clinically
significant drug interactions?
• A) CYP1A2
• B) CYP3A4
• C) CYP2D6
• D) CYP2E1
Rationale: CYP3A4 metabolizes >50% of drugs (e.g., statins, benzodiazepines,
calcium channel blockers).
9. A weak acid (pKa 4.5) will be mostly _____ in gastric fluid (pH 1.5).
• A) Non-ionized, favoring absorption
• B) Ionized, favoring excretion
• C) Trapped in stomach
• D) Precipitated
