Repeated USMLE Questions Step 1 Review- 131- Pharmacology

Q- A 64-year-old man with atrial fibrillation is started on warfarin therapy. After 3 days, he develops skin necrosis.

Which of the following best explains this complication?

A- Direct inhibition of thrombin

B- Immediate depletion of clotting factors II, VII, IX, X

C- Rapid decline in protein C leading to transient hypercoagulability

D- Vitamin K deficiency before therapy

C- Rapid decline in protein C leading to transient hypercoagulability- Warfarin inhibits vitamin K-dependent factors and protein C and S. Since protein C has a short half-life, it falls quickly, causing a temporary hypercoagulable state and skin necrosis in some patients.

 

Q- A 40-year-old man with peptic ulcer disease is started on omeprazole.

Which of the following is the primary mechanism of action of this medication?

A- Blocks H₂ receptors on gastric parietal cells

B- Irreversibly inhibits the H⁺/K⁺-ATPase pump in parietal cells

C- Neutralizes gastric acid by chemical reaction

D- Stimulates prostaglandin receptors in the gastric mucosa

B- Irreversibly inhibits the H⁺/K⁺-ATPase pump in parietal cells- Omeprazole is a proton pump inhibitor (PPI) that irreversibly blocks the H⁺/K⁺ ATPase in gastric parietal cells, leading to a profound reduction in gastric acid secretion.

 

Q- A 25-year-old woman with asthma presents to the emergency department with shortness of breath. She is given an inhaled medication that acts by stimulating β₂-adrenergic receptors, leading to smooth muscle relaxation in the bronchi.

Which of the following drugs was most likely administered?

A- Albuterol

B- Ipratropium

C- Propranolol

D- Theophylline

A- Albuterol- Albuterol is a short-acting β₂-adrenergic agonist used for rapid relief of acute bronchospasm in asthma.

 

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4 thoughts on “Repeated USMLE Questions Step 1 Review- 131- Pharmacology”

  1. Yes absolutely. Thank you for your feedback, my friend.

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  3. Thank you Dr. Mzahid Khan

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