Repeated USMLE Questions Step 1 Review-181- Pharmacology

Pharmacology MCQs for Medical Students
Test your pharmacology knowledge with high-yield clinical questions. Choose an answer, then check the correct answer and explanation.

Q– A patient with heart failure is prescribed a drug that inhibits the Na⁺/K⁺-ATPase pump, increasing intracellular calcium in cardiac myocytes.

Which one of the following drugs is most likely responsible?

A- Amiodarone

B- Digoxin

C- Diltiazem

D- Verapamil

Correct Answer

B- Digoxin- Digoxin inhibits the Na⁺/K⁺-ATPase pump, increasing intracellular sodium. This reduces Na⁺/Ca²⁺ exchange, leading to increased intracellular calcium and stronger cardiac contraction (positive inotropy).

 

Q– A patient taking an ACE inhibitor has developed a persistent cough. Which one of the following mediators is most responsible for this complaint?

A- Bradykinin

B- Histamine

C- Leukotriene B4

D- Serotonin

Correct Answer

A- Bradykinin- ACE inhibitors such as lisinopril reduce the breakdown of bradykinin, resulting in its accumulation. Elevated bradykinin contributes to dry cough and, in rare cases, angioedema.

 

Q– A patient treated for severe hypertension develops lupus-like syndrome, reflex tachycardia, and fluid retention.

Which mechanism best describes his medication?

A- Alpha-1 receptor blockade

B- Calcium channel blockade

C- Direct arteriolar vasodilation

D- Muscarinic antagonism

Correct Answer

C- Direct arteriolar vasodilation– Lupus-like syndrome, reflex tachycardia, and fluid retention are classic adverse effects of hydralazine. It directly relaxes the arteriolar smooth muscle, reducing afterload.

Hydralazine is a favorite USMLE clue.

 

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Dr Ray Makar

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