NUR 3123
Pharmacology
Final Exam Review
(Questions & Solutions)
2025
1
,1. A 55-year-old patient requires a loading dose of a new drug. The drug
has a volume of distribution (Vd) of 40 L and the target plasma
concentration is 10 mg/L. What loading dose will achieve this
concentration?
A. 100 mg
B. 400 mg
C. 800 mg
D. 1 600 mg
Correct ANS: C
Rationale: Loading dose = Vd × target concentration = 40 L × 10 mg/L
= 400 mg. If bioavailability is 50%, the oral loading dose must be doubled
to 800 mg.
---
2. A patient on a continuous intravenous infusion of Drug X reaches
steady state in 16 hours. The half-life (t½) of Drug X is most likely:
A. 1.6 hours
B. 4.0 hours
C. 8.0 hours
D. 16 hours
Correct ANS: B
Rationale: Steady state is reached after ~4–5 half-lives. 16 hours/4 ≈
4 hours.
---
3. Phenytoin follows zero-order kinetics at therapeutic levels. Which
statement describes its elimination?
A. Constant fraction of drug removed per hour
B. Constant amount of drug removed per hour
2
, C. First-order until saturation
D. Clearance directly proportional to dose
Correct ANS: B
Rationale: Zero-order kinetics means a constant amount (not
fraction) is eliminated per unit time regardless of concentration.
---
4. A competitive antagonist at a receptor will:
A. Lower the maximal effect (Emax) of the agonist
B. Increase the EC₅₀ of the agonist without changing Emax
C. Decrease the EC₅₀ and increase Emax
D. Convert a partial agonist into a full agonist
Correct ANS: B
Rationale: Competitive antagonists shift the dose–response curve
right (higher EC₅₀) but do not change the maximal achievable response.
---
5. Noncompetitive antagonism is characterized by:
A. Rightward parallel shift in dose–response curve
B. Downward shift in maximal effect (Emax)
C. Increased potency of the agonist
D. Reversible antagonism with high agonist concentrations
Correct ANS: B
Rationale: Noncompetitive antagonists reduce Emax because binding
cannot be overcome by more agonist; potency is unchanged.
---
6. Warfarin is metabolized primarily by CYP2C9. A polymorphism that
reduces CYP2C9 activity will:
3
, A. Decrease warfarin half-life and increase dose requirements
B. Increase warfarin half-life and decrease dose requirements
C. Have no effect on warfarin metabolism
D. Increase warfarin clearance
Correct ANS: B
Rationale: Reduced CYP2C9 activity slows warfarin metabolism,
prolongs half-life, and necessitates lower maintenance doses to avoid
bleeding.
---
7. A patient taking verapamil and digoxin develops 2nd-degree AV block.
Verapamil increases digoxin plasma levels by:
A. Inducing P-glycoprotein in the gut
B. Inhibiting P-glycoprotein–mediated secretion
C. Enhancing renal clearance of digoxin
D. Stimulating hepatic uptake
Correct ANS: B
Rationale: Verapamil inhibits P-glycoprotein, reducing digoxin efflux
into the gut and kidneys, raising serum levels and toxicity risk.
---
8. Rapid intravenous infusion of vancomycin can cause an infusion
reaction (“red man syndrome”). This is mediated by:
A. IgE-dependent mast cell degranulation
B. Direct histamine release from mast cells
C. Complement activation
D. Bradykinin accumulation
Correct ANS: B
Rationale: Vancomycin can directly trigger mast cell degranulation
and histamine release, causing flushing and hypotension.
4
Pharmacology
Final Exam Review
(Questions & Solutions)
2025
1
,1. A 55-year-old patient requires a loading dose of a new drug. The drug
has a volume of distribution (Vd) of 40 L and the target plasma
concentration is 10 mg/L. What loading dose will achieve this
concentration?
A. 100 mg
B. 400 mg
C. 800 mg
D. 1 600 mg
Correct ANS: C
Rationale: Loading dose = Vd × target concentration = 40 L × 10 mg/L
= 400 mg. If bioavailability is 50%, the oral loading dose must be doubled
to 800 mg.
---
2. A patient on a continuous intravenous infusion of Drug X reaches
steady state in 16 hours. The half-life (t½) of Drug X is most likely:
A. 1.6 hours
B. 4.0 hours
C. 8.0 hours
D. 16 hours
Correct ANS: B
Rationale: Steady state is reached after ~4–5 half-lives. 16 hours/4 ≈
4 hours.
---
3. Phenytoin follows zero-order kinetics at therapeutic levels. Which
statement describes its elimination?
A. Constant fraction of drug removed per hour
B. Constant amount of drug removed per hour
2
, C. First-order until saturation
D. Clearance directly proportional to dose
Correct ANS: B
Rationale: Zero-order kinetics means a constant amount (not
fraction) is eliminated per unit time regardless of concentration.
---
4. A competitive antagonist at a receptor will:
A. Lower the maximal effect (Emax) of the agonist
B. Increase the EC₅₀ of the agonist without changing Emax
C. Decrease the EC₅₀ and increase Emax
D. Convert a partial agonist into a full agonist
Correct ANS: B
Rationale: Competitive antagonists shift the dose–response curve
right (higher EC₅₀) but do not change the maximal achievable response.
---
5. Noncompetitive antagonism is characterized by:
A. Rightward parallel shift in dose–response curve
B. Downward shift in maximal effect (Emax)
C. Increased potency of the agonist
D. Reversible antagonism with high agonist concentrations
Correct ANS: B
Rationale: Noncompetitive antagonists reduce Emax because binding
cannot be overcome by more agonist; potency is unchanged.
---
6. Warfarin is metabolized primarily by CYP2C9. A polymorphism that
reduces CYP2C9 activity will:
3
, A. Decrease warfarin half-life and increase dose requirements
B. Increase warfarin half-life and decrease dose requirements
C. Have no effect on warfarin metabolism
D. Increase warfarin clearance
Correct ANS: B
Rationale: Reduced CYP2C9 activity slows warfarin metabolism,
prolongs half-life, and necessitates lower maintenance doses to avoid
bleeding.
---
7. A patient taking verapamil and digoxin develops 2nd-degree AV block.
Verapamil increases digoxin plasma levels by:
A. Inducing P-glycoprotein in the gut
B. Inhibiting P-glycoprotein–mediated secretion
C. Enhancing renal clearance of digoxin
D. Stimulating hepatic uptake
Correct ANS: B
Rationale: Verapamil inhibits P-glycoprotein, reducing digoxin efflux
into the gut and kidneys, raising serum levels and toxicity risk.
---
8. Rapid intravenous infusion of vancomycin can cause an infusion
reaction (“red man syndrome”). This is mediated by:
A. IgE-dependent mast cell degranulation
B. Direct histamine release from mast cells
C. Complement activation
D. Bradykinin accumulation
Correct ANS: B
Rationale: Vancomycin can directly trigger mast cell degranulation
and histamine release, causing flushing and hypotension.
4
