Final Exam & Pre-Assessment Practice
300 Questions with Detailed Answers and Rationales
1. A patient with a history of heart failure is prescribed metoprolol succinate. Which property of this
drug makes it preferred over metoprolol tartrate for chronic heart failure management?
A) Shorter half-life allowing rapid titration
B) Extended-release formulation providing consistent beta-1 blockade
C) Greater lipophilicity for CNS penetration
D) Higher peak plasma concentration for rapid symptom relief
Answer: B
Rationale: Metoprolol succinate is an extended-release formulation that provides consistent 24-hour beta-1
blockade, which is essential for chronic heart failure management. Metoprolol tartrate is immediate-release
and requires multiple daily dosing. The extended-release formulation has been shown to reduce mortality in
HFrEF. Shorter half-life (A) would be a disadvantage for chronic management. Greater lipophilicity (C) is not
the reason for preference. Higher peak concentrations (D) may actually increase adverse effects.
2. A patient on warfarin therapy has an INR of 6.5 but is not actively bleeding. Which intervention is
most appropriate?
A) Administer vitamin K 10 mg IV and hold warfarin
B) Hold warfarin and administer vitamin K 2.5 mg PO
C) Continue warfarin at the same dose and recheck in 24 hours
D) Administer fresh frozen plasma immediately
Answer: B
Rationale: For an INR of 6.5 without bleeding, the recommendation is to hold warfarin and give low-dose
oral vitamin K (2.5 mg). High-dose IV vitamin K (A) is reserved for serious bleeding and can cause warfarin
resistance. Continuing the same dose (C) is unsafe. FFP (D) is for active bleeding or emergent reversal.
3. Which cytochrome P450 enzyme is responsible for the metabolism of approximately 50% of all
drugs?
A) CYP1A2
B) CYP2D6
,C) CYP3A4
D) CYP2C9
Answer: C
Rationale: CYP3A4 is the most abundant CYP450 enzyme in the liver and intestine, metabolizing
approximately 50% of drugs. CYP2D6 metabolizes about 25%, CYP2C9 about 15%, and CYP1A2 about 5%.
4. A patient with type 2 diabetes on metformin is scheduled for a contrast-enhanced CT scan. What is
the most appropriate action regarding metformin?
A) Continue metformin as usual
B) Discontinue metformin 48 hours before the procedure
C) Reduce metformin dose by half
D) Administer IV sodium bicarbonate before the procedure
Answer: B
Rationale: Iodinated contrast can transiently impair renal function, increasing the risk of metformin
accumulation and lactic acidosis. Guidelines recommend discontinuing metformin 48 hours before contrast
administration and restarting after renal function is confirmed. Continuing (A) is unsafe. Dose reduction (C)
is not standard. Sodium bicarbonate (D) is not indicated.
5. Which pharmacokinetic parameter determines the loading dose of a drug?
A) Clearance
B) Volume of distribution
C) Half-life
D) Bioavailability
Answer: B
Rationale: Loading dose = (Vd × Target concentration) / Bioavailability. Vd determines the amount of drug
needed to fill the body's distribution volume. Clearance determines maintenance dose. Half-life determines
time to steady state. Bioavailability affects both but is not the primary determinant.
6. A patient with severe renal impairment (CrCl 15 mL/min) is prescribed enoxaparin. What dose
adjustment is required?
A) No adjustment needed
B) Reduce dose by 50%
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,C) Increase dose by 25%
D) Administer only with protamine
Answer: B
Rationale: Enoxaparin is renally eliminated. In severe renal impairment (CrCl <30 mL/min), the dose
should be reduced by 50% (to 1 mg/kg once daily for treatment or 30 mg once daily for prophylaxis) to
prevent accumulation and bleeding. No adjustment (A) risks bleeding. Increasing dose (C) is dangerous.
Protamine (D) is an antidote, not a dosing strategy.
7. Which drug is a direct factor Xa inhibitor?
A) Dabigatran
B) Rivaroxaban
C) Warfarin
D) Heparin
Answer: B
Rationale: Rivaroxaban directly inhibits factor Xa. Dabigatran is a direct thrombin inhibitor. Warfarin is a
vitamin K antagonist. Heparin activates antithrombin III.
8. A patient on digoxin presents with nausea, vomiting, and yellow-green visual halos. Which
electrolyte abnormality most likely contributes to this presentation?
A) Hyperkalemia
B) Hypokalemia
C) Hypernatremia
D) Hypocalcemia
Answer: B
Rationale: Hypokalemia increases digoxin binding to Na+/K+-ATPase, enhancing toxicity. Symptoms
include GI upset, visual disturbances, and arrhythmias. Hyperkalemia (A) is seen in acute toxicity but does
not predispose. Sodium and calcium abnormalities are not directly linked.
9. Which statement best describes the mechanism of action of sacubitril/valsartan?
A) Inhibits neprilysin and blocks angiotensin II receptors
B) Inhibits ACE and blocks angiotensin II receptors
C) Inhibits renin and blocks aldosterone receptors
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, D) Inhibits neprilysin and blocks beta-adrenergic receptors
Answer: A
Rationale: Sacubitril inhibits neprilysin, increasing natriuretic peptides. Valsartan blocks AT1 receptors.
This dual mechanism reduces mortality in HFrEF. ACE inhibition (B) is not part of this combination. Renin
inhibition (C) describes aliskiren. Beta-blockade (D) is not involved.
10. A patient with asthma is prescribed a beta-blocker. Which agent is safest?
A) Propranolol
B) Metoprolol
C) Carvedilol
D) Labetalol
Answer: B
Rationale: Metoprolol is cardioselective (beta-1), making it safer in asthma than non-selective agents.
Propranolol, carvedilol, and labetalol are non-selective and can cause bronchoconstriction. However, all
beta-blockers should be used cautiously in asthma.
11. Which drug is a potent inhibitor of CYP3A4?
A) Rifampin
B) Carbamazepine
C) Ketoconazole
D) Phenytoin
Answer: C
Rationale: Ketoconazole is a potent CYP3A4 inhibitor. Rifampin, carbamazepine, and phenytoin are
inducers.
12. A patient on phenytoin has a serum level of 25 mcg/mL (therapeutic: 10-20 mcg/mL). Which
adverse effect is most likely?
A) Gingival hyperplasia
B) Nystagmus and ataxia
C) Hirsutism
D) Osteomalacia
Answer: B
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