Antiplatelet Agents Quiz: Aspirin & Clopidogrel

1. What is the typical maintenance dose of aspirin for antiplatelet effect?

81–325 mg once daily

500 mg three times daily

1000 mg twice daily

50 mg every 6 hours

2. What is the mechanism by which proton pump inhibitors reduce clopidogrel effectiveness?

Decreased GI absorption

Inhibition of CYP2C19 enzyme

Increased platelet aggregation

Accelerated renal clearance

3. Clopidogrel is preferred over aspirin in patients with which condition?

Aspirin allergy or intolerance

Mild hypertension

Hyperlipidemia

Type 1 diabetes

4. A patient with a history of stroke is prescribed aspirin. What is the primary goal of this therapy?

Prevent recurrent ischemic stroke

Treat existing blood clots

Lower blood pressure

Reduce fever

5. Which CYP450 enzyme is primarily responsible for clopidogrel bioactivation?

CYP2C9

CYP3A4

CYP2C19

CYP1A2

6. Aspirin irreversibly inhibits platelet aggregation for the lifespan of the platelet. How long does platelet recovery take after stopping aspirin?

2–3 hours

1–2 days

7–10 days

Permanent; never recovers

7. How long should dual antiplatelet therapy (DAPT) typically be continued after acute coronary syndrome (ACS)?

1 week

1–12 months depending on stent type and risk

Lifelong

Only during hospitalization

8. A patient on aspirin therapy experiences tinnitus and altered mental status. What condition should be suspected?

Aspirin toxicity (salicylism)

Allergic reaction

Thrombocytopenia

Stroke

9. Thrombotic thrombocytopenic purpura (TTP) is a rare but serious adverse effect of which antiplatelet agent?

Aspirin only

Clopidogrel

Both equally

Neither; unrelated to antiplatelets

10. Clopidogrel has significant interaction with which class of medications?

Proton pump inhibitors (PPIs)

Antihistamines

Antacids without interaction

Vitamins and minerals

11. What is the primary mechanism of action for aspirin as an antiplatelet agent?

Irreversible inhibition of cyclooxygenase (COX)

Competitive antagonism of P2Y12 receptors

Direct thrombin inhibition

Inhibition of platelet phosphodiesterase

12. Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is indicated after which procedure?

Routine blood pressure check

Percutaneous coronary intervention (PCI) with stent

Chest X-ray

Electrocardiogram

13. A patient has aspirin allergy. Which antiplatelet agent is a safe alternative?

Clopidogrel

Acetaminophen

Ibuprofen

Naproxen

14. Clopidogrel is a prodrug. Which organ is responsible for its activation?

Kidney

Bone marrow

Liver

Spleen

15. Which adverse effect is most commonly associated with chronic aspirin use?

Hyperkalemia

Gastrointestinal bleeding

Acute kidney injury

Pulmonary edema

16. A patient on clopidogrel requires urgent surgery. What is the recommended action?

Continue clopidogrel; no surgical delay needed

Hold clopidogrel 5–7 days preoperatively if possible

Immediately reverse with vitamin K

Switch to aspirin the day before surgery

17. Aspirin is contraindicated in patients with which condition?

Type 2 diabetes mellitus

Active peptic ulcer disease

Hypertension

Atrial fibrillation

18. Which statement correctly describes the onset of action for clopidogrel?

Immediate effect within 15 minutes

Requires hepatic metabolism; peak effect 3–7 days

Achieves maximum effect in 1 hour

No loading dose is ever needed

19. Clopidogrel exerts its antiplatelet effect through which mechanism?

Irreversible COX inhibition

Irreversible P2Y12 receptor antagonism

Reversible thrombin inhibition

Platelet surface glycoprotein blockade

Antiplatelet Quiz: Aspirin or Clopidogrel?