Advanced Pharmacology
Final Practice Exam
Topics Covered: Pharmacokinetics & Pharmacodynamics • Cardiovascular •
CNS & Psychiatric • Antimicrobial • Endocrine • Respiratory • Gastrointestinal
• Pain Management & Anticoagulation • Renal/Fluid/Electrolyte • Special
Populations, Pharmacogenomics & Toxicology
,Pharmacokinetics & Pharmacodynamics
Question 1. A patient with severe hepatic cirrhosis is prescribed a drug
that is highly protein-bound and undergoes extensive first-pass
metabolism. Which pharmacokinetic change is most likely?
A. Decreased free drug concentration and decreased effect
B. Increased free drug fraction and increased risk of toxicity
C. Decreased volume of distribution
D. Increased renal clearance of the parent drug
Correct Answer: B
Rationale: In hepatic cirrhosis, albumin synthesis is reduced, decreasing
protein binding capacity. This increases the free (unbound, active) fraction of
highly protein-bound drugs, raising the risk of toxicity. Reduced first-pass
metabolism also increases bioavailability of oral drugs, compounding the
effect.
Question 2. Which term describes the percentage of an administered
drug dose that reaches systemic circulation unchanged?
A. Volume of distribution
B. Bioavailability
C. Clearance
D. Half-life
Correct Answer: B
Rationale: Bioavailability is defined as the fraction of an administered dose
that reaches systemic circulation unchanged. IV drugs have 100%
bioavailability; oral drugs are typically lower due to first-pass hepatic
metabolism and incomplete absorption.
,Question 3. A drug has a half-life of 6 hours. Approximately how long
will it take to reach steady-state plasma concentration with regular
dosing?
A. 6 hours
B. 12 hours
C. 24-30 hours
D. 60 hours
Correct Answer: C
Rationale: Steady state is reached after approximately 4-5 half-lives
regardless of dose or dosing interval. With a 6-hour half-life, 4-5 half-lives
equals 24-30 hours.
Question 4. Which cytochrome P450 enzyme is responsible for the
metabolism of the greatest number of clinically used drugs?
A. CYP1A2
B. CYP2D6
C. CYP3A4
D. CYP2C9
Correct Answer: C
Rationale: CYP3A4 metabolizes approximately 50% of all clinically
prescribed drugs and is highly susceptible to inhibition (e.g., by grapefruit
juice, azole antifungals) and induction (e.g., by rifampin, carbamazepine),
making it central to many drug interactions.
Question 5. A patient taking warfarin is started on a strong CYP2C9
inhibitor. What is the expected effect on the INR?
A. Decreased INR due to faster warfarin clearance
B. No change, as warfarin is not metabolized by CYP enzymes
C. Increased INR due to reduced warfarin metabolism
D. Increased INR due to enhanced vitamin K synthesis
Correct Answer: C
Rationale: Warfarin's more potent S-enantiomer is metabolized primarily by
CYP2C9. Inhibition of this enzyme slows warfarin clearance, raising plasma
levels and INR, increasing bleeding risk.
, Question 6. Which factor most directly determines the loading dose of a
medication?
A. Half-life
B. Volume of distribution
C. Clearance
D. Bioavailability of the IV formulation
Correct Answer: B
Rationale: Loading dose = (Volume of distribution x desired plasma
concentration) / bioavailability. Volume of distribution reflects how extensively
a drug distributes into tissues versus remaining in plasma, and directly
determines the dose needed to rapidly achieve a target concentration.
Question 7. A drug exhibits zero-order kinetics at therapeutic doses.
What does this indicate?
A. A constant fraction of drug is eliminated per unit time
B. A constant amount of drug is eliminated per unit time regardless of
concentration
C. Elimination rate is proportional to plasma concentration
D. The drug has an extremely short half-life
Correct Answer: B
Rationale: Zero-order kinetics means elimination pathways are saturated, so
a constant amount (not percentage) is eliminated per unit time. Phenytoin,
alcohol, and high-dose aspirin are classic examples; small dose increases
can cause disproportionate rises in plasma levels.