FUNDAMENTALS 250-Questions Practice Exam
| Questions and Answers & Rationales
1. Which pharmacokinetic process involves the movement of a drug from its
site of administration into the bloodstream?
A) Distribution
B) *Absorption
C) Metabolism
D) Excretion
Answer: B
Rationale: Absorption is the transfer of a drug from the site of administration to
systemic circulation.
2. The volume of distribution (Vd) of a drug is best described as:
A) The amount of drug in the liver
B) *The theoretical volume into which the total drug dose distributes
C) The rate of renal clearance
D) The plasma protein binding percentage
Answer: B
Rationale: Vd relates total drug in body to plasma concentration; high Vd
indicates extensive tissue distribution.
,3. Which organ is primarily responsible for drug metabolism?
A) Kidney
B) *Liver
C) Lungs
D) Stomach
Answer: B
Rationale: The liver is the main site of phase I and phase II drug metabolism.
4. A drug with a half-life of 6 hours will reach steady state in approximately:
A) 6 hours
B) 12 hours
C) *30 hours
D) 60 hours
Answer: C
Rationale: Steady state is reached after about 5 half-lives (5 × 6 = 30 hours).
5. Which route of administration bypasses first-pass metabolism?
A) Oral
B) *Intravenous
C) Rectal
D) Sublingual
Answer: B
,Rationale: IV administration enters systemic circulation directly, avoiding hepatic
first-pass metabolism.
6. A loading dose is used to:
A) Maintain steady-state levels
B) *Rapidly achieve therapeutic drug concentration
C) Reduce adverse effects
D) Prolong half-life
Answer: B
Rationale: Loading dose rapidly attains target concentration before maintenance
dosing.
7. Which receptor type is coupled to G proteins?
A) Ligand-gated ion channel
B) *G protein-coupled receptor
C) Tyrosine kinase receptor
D) Nuclear receptor
Answer: B
Rationale: GPCRs activate second messengers via G proteins.
8. A competitive antagonist:
A) Irreversibly binds the receptor
, B) *Shifts the agonist dose-response curve right
C) Decreases agonist efficacy
D) Increases agonist potency
Answer: B
Rationale: Competitive antagonists increase the EC50 but do not reduce maximal
efficacy.
9. The therapeutic index is:
A) ED50/LD50
B) *TD50/ED50
C) LD50/ED50
D) EC50/ED50
Answer: B
Rationale: Therapeutic index = toxic dose 50 / effective dose 50; higher is safer.
10. Which phase of metabolism involves conjugation reactions?
A) Phase I
B) *Phase II
C) Phase III
D) Phase 0
Answer: B
Rationale: Phase II reactions conjugate drugs with glucuronic acid, sulfate, etc.,
increasing water solubility.