Master RN Pharmacology Exam Prep: 150 High‑Yield Questions with
Verified Answers and Detailed Rationales Drawn from the Best of v1,
v2, and v3 — Calling All Drug Classes, Antidotes, Interactions, and
NCLEX Clinical Judgment.
Section 1: Anticoagulants & Antiplatelets (1–
12)
1. A patient on warfarin has an INR of 4.5 without bleeding. What
is the most appropriate action?
A. Give vitamin K 10 mg IV
B. Hold warfarin and recheck INR in 1–2 days
C. Give fresh frozen plasma
D. Increase warfarin dose
Answer: B – For INR 4.5–9 without bleeding, hold warfarin and
monitor.
2. A patient on warfarin is started on
sulfamethoxazole‑trimethoprim. What INR change is expected?
A. INR decreases
B. INR increases (TMP‑SMX inhibits warfarin metabolism)
C. No change
D. Unpredictable
Answer: B – TMP‑SMX is a strong CYP2C9 inhibitor; reduce warfarin
dose.
,3. A patient on apixaban develops a life‑threatening bleed. Which
reversal agent is indicated?
A. Protamine sulfate
B. Vitamin K
C. Andexanet alfa
D. Idarucizumab
Answer: C – Andexanet alfa (Andexxa) reverses apixaban and
rivaroxaban.
4. A patient with HIT (heparin‑induced thrombocytopenia) has a
platelet count of 40,000. Which drug should be used instead of
heparin?
A. Warfarin
B. Argatroban
C. Enoxaparin
D. Bivalirudin
Answer: D – Direct thrombin inhibitors (argatroban, bivalirudin) are
first‑line.
5. A patient receiving IV unfractionated heparin has an aPTT of
110 seconds (control 30 seconds). What action is correct?
A. Increase heparin drip rate
B. Hold heparin for 1 hour and recheck
C. Give protamine sulfate
D. No change
Answer: B – Hold heparin for 30–60 minutes; aPTT >100 seconds
increases bleeding risk.
6. A patient on clopidogrel for acute coronary syndrome is
scheduled for surgery. How many days before surgery should it
be stopped?
,A. 1 day
B. 3 days
C. 5–7 days
D. 14 days
Answer: C – Clopidogrel should be stopped 5–7 days
pre‑operatively.
7. A patient on warfarin has an INR of 1.2 while on a heparin drip.
When should warfarin be started?
A. Same day as heparin
B. Overlap heparin and warfarin for ≥5 days until INR >2 for 24
hours
C. Stop heparin, then start warfarin
D. Warfarin alone is sufficient
Answer: B – Overlap therapy until therapeutic INR; heparin protects
initially.
8. Which anticoagulant is safe to use in patients with mechanical
heart valves?
A. Dabigatran
B. Apixaban
C. Warfarin
D. Rivaroxaban
Answer: C – Warfarin is the only approved oral anticoagulant for
mechanical valves.
9. A patient on aspirin 81 mg daily for secondary prevention
develops GI bleeding. What is the best long‑term strategy?
A. Stop aspirin permanently
B. Restart aspirin plus PPI
C. Switch to clopidogrel alone
, D. Double aspirin dose
Answer: B – After bleeding controlled, restart aspirin with PPI.
10. A patient on ticagrelor reports dyspnea. What is the likely
cause?
A. Heart failure
B. Ticagrelor side effect (dyspnea in ~14%)
C. Pulmonary embolism
D. Asthma
Answer: B – Ticagrelor causes dyspnea via adenosine accumulation;
self‑limiting.
11. Which factor Xa inhibitor has a specific reversal agent?
A. Rivaroxaban
B. Apixaban
C. Edoxaban
D. All of the above (andexanet alfa)
Answer: D – Andexanet alfa reverses all three factor Xa inhibitors.
12. A patient on prasugrel has a history of prior stroke. Why is this
concerning?
A. Increased bleeding risk
B. Prasugrel is contraindicated in prior stroke/TIA (higher ICH)
C. No interaction
D. Decreased efficacy
Answer: B – Prasugrel contraindicated in patients with prior
stroke/TIA.
Verified Answers and Detailed Rationales Drawn from the Best of v1,
v2, and v3 — Calling All Drug Classes, Antidotes, Interactions, and
NCLEX Clinical Judgment.
Section 1: Anticoagulants & Antiplatelets (1–
12)
1. A patient on warfarin has an INR of 4.5 without bleeding. What
is the most appropriate action?
A. Give vitamin K 10 mg IV
B. Hold warfarin and recheck INR in 1–2 days
C. Give fresh frozen plasma
D. Increase warfarin dose
Answer: B – For INR 4.5–9 without bleeding, hold warfarin and
monitor.
2. A patient on warfarin is started on
sulfamethoxazole‑trimethoprim. What INR change is expected?
A. INR decreases
B. INR increases (TMP‑SMX inhibits warfarin metabolism)
C. No change
D. Unpredictable
Answer: B – TMP‑SMX is a strong CYP2C9 inhibitor; reduce warfarin
dose.
,3. A patient on apixaban develops a life‑threatening bleed. Which
reversal agent is indicated?
A. Protamine sulfate
B. Vitamin K
C. Andexanet alfa
D. Idarucizumab
Answer: C – Andexanet alfa (Andexxa) reverses apixaban and
rivaroxaban.
4. A patient with HIT (heparin‑induced thrombocytopenia) has a
platelet count of 40,000. Which drug should be used instead of
heparin?
A. Warfarin
B. Argatroban
C. Enoxaparin
D. Bivalirudin
Answer: D – Direct thrombin inhibitors (argatroban, bivalirudin) are
first‑line.
5. A patient receiving IV unfractionated heparin has an aPTT of
110 seconds (control 30 seconds). What action is correct?
A. Increase heparin drip rate
B. Hold heparin for 1 hour and recheck
C. Give protamine sulfate
D. No change
Answer: B – Hold heparin for 30–60 minutes; aPTT >100 seconds
increases bleeding risk.
6. A patient on clopidogrel for acute coronary syndrome is
scheduled for surgery. How many days before surgery should it
be stopped?
,A. 1 day
B. 3 days
C. 5–7 days
D. 14 days
Answer: C – Clopidogrel should be stopped 5–7 days
pre‑operatively.
7. A patient on warfarin has an INR of 1.2 while on a heparin drip.
When should warfarin be started?
A. Same day as heparin
B. Overlap heparin and warfarin for ≥5 days until INR >2 for 24
hours
C. Stop heparin, then start warfarin
D. Warfarin alone is sufficient
Answer: B – Overlap therapy until therapeutic INR; heparin protects
initially.
8. Which anticoagulant is safe to use in patients with mechanical
heart valves?
A. Dabigatran
B. Apixaban
C. Warfarin
D. Rivaroxaban
Answer: C – Warfarin is the only approved oral anticoagulant for
mechanical valves.
9. A patient on aspirin 81 mg daily for secondary prevention
develops GI bleeding. What is the best long‑term strategy?
A. Stop aspirin permanently
B. Restart aspirin plus PPI
C. Switch to clopidogrel alone
, D. Double aspirin dose
Answer: B – After bleeding controlled, restart aspirin with PPI.
10. A patient on ticagrelor reports dyspnea. What is the likely
cause?
A. Heart failure
B. Ticagrelor side effect (dyspnea in ~14%)
C. Pulmonary embolism
D. Asthma
Answer: B – Ticagrelor causes dyspnea via adenosine accumulation;
self‑limiting.
11. Which factor Xa inhibitor has a specific reversal agent?
A. Rivaroxaban
B. Apixaban
C. Edoxaban
D. All of the above (andexanet alfa)
Answer: D – Andexanet alfa reverses all three factor Xa inhibitors.
12. A patient on prasugrel has a history of prior stroke. Why is this
concerning?
A. Increased bleeding risk
B. Prasugrel is contraindicated in prior stroke/TIA (higher ICH)
C. No interaction
D. Decreased efficacy
Answer: B – Prasugrel contraindicated in patients with prior
stroke/TIA.
