NAPLEX QBANK Pharmacology and Mechanism of Action 5

Question 1

Which mechanism explains the action of direct oral anticoagulant apixaban?

Accepted Answer

Direct factor Xa inhibition

Answer

Direct thrombin (factor IIa) inhibition

Answer

Antithrombin III potentiation

Answer

Vitamin K antagonism

Question 2

Dabigatran differs from apixaban in that it:

Accepted Answer

Directly inhibits thrombin (IIa)

Answer

Inhibits factor Xa

Answer

Antagonizes vitamin K

Answer

Requires antithrombin as a cofactor

Question 3

The mechanism of action of SGLT2 inhibitors (e.g., empagliflozin) is:

Accepted Answer

Blocking renal proximal tubule glucose reabsorption

Answer

Stimulating insulin secretion

Answer

Decreasing hepatic gluconeogenesis

Answer

Slowing gastric emptying

Question 4

GLP-1 receptor agonists (e.g., semaglutide) lower glucose by:

Accepted Answer

Enhancing glucose-dependent insulin secretion and slowing gastric emptying

Answer

Inhibiting DPP-4 directly

Answer

Blocking SGLT2

Answer

Inhibiting alpha-glucosidase

Question 5

Which drug class inhibits the breakdown of incretins to lower blood glucose?

Accepted Answer

DPP-4 inhibitors (e.g., sitagliptin)

Answer

Sulfonylureas

Answer

Thiazolidinediones

Answer

Biguanides

Question 6

Spironolactone exerts its diuretic and potassium-sparing effect by:

Accepted Answer

Antagonizing aldosterone receptors in the distal nephron

Answer

Inhibiting the Na-K-2Cl transporter

Answer

Inhibiting carbonic anhydrase

Answer

Blocking the Na-Cl cotransporter

Question 7

The mechanism of action of fluoroquinolones (e.g., levofloxacin) is:

Accepted Answer

Inhibition of DNA gyrase and topoisomerase IV

Answer

Inhibition of the 50S ribosome

Answer

Disruption of cell wall synthesis

Answer

Inhibition of RNA polymerase