NAPLEX QBANK Pharmacology and Drug Mechanisms 2

Question 1

Which mechanism explains the antiplatelet effect of clopidogrel?

Accepted Answer

Irreversible P2Y12 ADP receptor blockade

Answer

COX-1 acetylation

Answer

GP IIb/IIIa receptor antagonism

Answer

Phosphodiesterase-3 inhibition

Question 2

A patient on warfarin starts amiodarone; what is the expected interaction?

Accepted Answer

Increased INR from CYP2C9/CYP3A4 inhibition

Answer

Decreased INR from enzyme induction

Answer

No interaction

Answer

Decreased warfarin absorption

Question 3

Which diuretic acts on the Na-K-2Cl cotransporter in the thick ascending limb?

Accepted Answer

Furosemide

Answer

Hydrochlorothiazide

Answer

Spironolactone

Answer

Acetazolamide

Question 4

The mechanism of metformin's glucose-lowering effect primarily involves:

Accepted Answer

AMPK activation and decreased hepatic gluconeogenesis

Answer

Stimulation of insulin secretion

Answer

Inhibition of intestinal alpha-glucosidase

Answer

SGLT2 inhibition in the proximal tubule

Question 5

Which receptor does ondansetron antagonize to prevent nausea?

Accepted Answer

5-HT3 serotonin receptor

Answer

D2 dopamine receptor

Answer

H1 histamine receptor

Answer

NK1 substance P receptor

Question 6

What best describes the action of sacubitril in sacubitril/valsartan?

Accepted Answer

Neprilysin inhibition increasing natriuretic peptides

Answer

ACE inhibition

Answer

Beta-1 receptor blockade

Answer

Aldosterone receptor antagonism

Question 7

Which agent is a selective beta-2 agonist used for acute bronchospasm?

Accepted Answer

Albuterol

Answer

Metoprolol

Answer

Atenolol

Answer

Carvedilol