NAPLEX QBANK Pharmacology and Mechanism of Action 3

Question 1

Which antibiotic mechanism is associated with inhibition of the 50S ribosomal subunit?

Accepted Answer

Macrolides such as azithromycin

Answer

Fluoroquinolones such as ciprofloxacin

Answer

Aminoglycosides such as gentamicin

Answer

Beta-lactams such as amoxicillin

Question 2

Phenytoin exerts its antiseizure effect mainly by:

Accepted Answer

Blocking voltage-gated sodium channels

Answer

Enhancing GABA-A chloride influx

Answer

Blocking T-type calcium channels

Answer

Antagonizing NMDA receptors

Question 3

Why must aminoglycosides be dosed carefully with monitoring?

Accepted Answer

Narrow therapeutic index with nephro- and ototoxicity

Answer

They are CYP3A4 inducers

Answer

They cause QT prolongation primarily

Answer

They are highly protein bound

Question 4

Which drug increases insulin secretion by closing pancreatic K-ATP channels?

Accepted Answer

Glipizide (sulfonylurea)

Answer

Pioglitazone

Answer

Acarbose

Answer

Empagliflozin

Question 5

The mechanism of action of digoxin includes:

Accepted Answer

Inhibition of Na+/K+ ATPase increasing intracellular calcium

Answer

Blockade of beta-1 adrenergic receptors

Answer

Calcium channel blockade in the AV node only

Answer

Direct ACE inhibition

Question 6

Which class blocks angiotensin II at the AT1 receptor without raising bradykinin?

Accepted Answer

ARBs such as losartan

Answer

ACE inhibitors such as lisinopril

Answer

Direct renin inhibitors such as aliskiren

Answer

Aldosterone antagonists such as spironolactone

Question 7

SSRIs relieve depression by:

Accepted Answer

Blocking presynaptic serotonin reuptake transporters

Answer

Inhibiting monoamine oxidase

Answer

Blocking dopamine D2 receptors

Answer

Agonizing GABA-B receptors