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).
The correct answer is B-Digoxin
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.
Read this Pharmacology MCQs Book
More Pharmacology MCQs
