NAPLEX QBANK Pharmacology and Drug Mechanisms 5

Question 1

Which mechanism describes digoxin's positive inotropic effect?

Accepted Answer

Inhibition of Na+/K+ ATPase increasing intracellular calcium

Answer

Digoxin inhibits Na+/K+ ATPase, indirectly raising intracellular calcium for stronger contraction.

Question 2

Which anticoagulant directly inhibits factor Xa?

Accepted Answer

Rivaroxaban

Answer

Rivaroxaban is a direct oral factor Xa inhibitor.

Question 3

Beta-blockers reduce heart rate primarily by antagonizing which receptor?

Accepted Answer

Beta-1 adrenergic receptors

Answer

Blocking cardiac beta-1 receptors decreases heart rate and contractility.

Question 4

Which drug interaction increases risk of serotonin syndrome?

Accepted Answer

SSRI plus MAO inhibitor

Answer

Combining serotonergic agents like SSRIs with MAOIs can cause serotonin syndrome.

Question 5

ACE inhibitors cause cough primarily due to accumulation of:

Accepted Answer

Bradykinin

Answer

ACE also degrades bradykinin; its buildup triggers the characteristic dry cough.

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