NBME Pharmacology 2 — Questions and Answers
Question 1: A patient on warfarin presents with INR of 8 and active bleeding. Which agent provides the most rapid reversal of warfarin anticoagulation?
- Vitamin K (oral)
- Fresh frozen plasma (Correct answer)
- Protamine sulfate
- Tranexamic acid
Correct answer: Fresh frozen plasma
Fresh frozen plasma provides immediate replenishment of all clotting factors and is the fastest reversal for life-threatening warfarin-related bleeding.
Question 2: Which mechanism best explains why ACE inhibitors cause a dry cough in approximately 10-15% of patients?
- Increased bradykinin accumulation in the lungs (Correct answer)
- Decreased angiotensin II production
- Direct bronchospasm from ACE inhibition
- Potassium retention causing airway irritation
Correct answer: Increased bradykinin accumulation in the lungs
ACE inhibitors block the breakdown of bradykinin, causing its accumulation in pulmonary tissue and stimulating cough receptors.
Question 3: A 72-year-old patient develops confusion, bradycardia, and yellow-green visual disturbances while on a drug for atrial fibrillation. Toxicity from which drug best explains these findings?
- Amiodarone
- Digoxin (Correct answer)
- Metoprolol
- Diltiazem
Correct answer: Digoxin
Digoxin toxicity classically presents with visual changes (xanthopsia), GI upset, and arrhythmias including bradycardia, particularly in elderly patients.
Question 4: Aminoglycosides such as gentamicin are associated with nephrotoxicity. Which nephron segment is primarily damaged?
- Glomerulus
- Proximal tubule (Correct answer)
- Loop of Henle
- Collecting duct
Correct answer: Proximal tubule
Aminoglycosides accumulate in proximal tubular cells via endocytosis and cause direct tubular cell necrosis.
Question 5: A patient is receiving heparin for a DVT. Her platelet count drops from 250,000 to 60,000 after 8 days of therapy. Which drug should be used to continue anticoagulation?
- Low molecular weight heparin
- Warfarin
- Argatroban (Correct answer)
- Aspirin
Correct answer: Argatroban
Heparin-induced thrombocytopenia (HIT) requires immediate discontinuation of all heparin products and substitution with a direct thrombin inhibitor such as argatroban.
Question 6: Which beta-blocker property makes carvedilol preferable over metoprolol in patients with heart failure and peripheral vascular disease?
- Cardioselectivity for beta-1 receptors
- Alpha-1 blocking activity causing vasodilation (Correct answer)
- Intrinsic sympathomimetic activity
- Membrane-stabilizing activity
Correct answer: Alpha-1 blocking activity causing vasodilation
Carvedilol blocks alpha-1 receptors in addition to beta receptors, causing peripheral vasodilation that benefits patients with peripheral vascular disease.
Question 7: A child is brought to the ER after ingesting penicillin tablets. Allergic reaction to penicillin is most commonly mediated by which mechanism?
- Type I (IgE-mediated) hypersensitivity (Correct answer)
- Type II (cytotoxic) hypersensitivity
- Type III (immune complex) hypersensitivity
- Type IV (delayed-type) hypersensitivity
Correct answer: Type I (IgE-mediated) hypersensitivity
The most common and clinically significant penicillin reactions are IgE-mediated (Type I), which can cause anaphylaxis within minutes of exposure.
NBME Pharmacology 2
A patient on warfarin presents with INR of 8 and active bleeding.
Which agent provides the most rapid reversal of warfarin anticoagulation?