COMLEX-USA Pharmacology 3

Question 1

Which drug class is the first-line treatment for chronic stable angina and works by reducing myocardial oxygen demand?

Accepted Answer

Beta-blockers

Answer

Beta-blockers reduce heart rate and contractility, decreasing myocardial oxygen demand and are first-line for chronic stable angina prophylaxis.

Question 2

Fluconazole treats fungal infections by inhibiting which enzyme, reducing ergosterol synthesis?

Accepted Answer

14-alpha demethylase (CYP51)

Answer

Azole antifungals including fluconazole inhibit CYP51 (lanosterol 14-alpha demethylase), blocking ergosterol synthesis and disrupting fungal cell membranes.

Question 3

A patient on isoniazid (INH) develops peripheral neuropathy. Which supplement should be given to prevent this side effect?

Accepted Answer

Vitamin B6 (pyridoxine)

Answer

INH inhibits pyridoxine (B6) metabolism; supplementing pyridoxine prevents INH-induced peripheral neuropathy.

Question 4

The therapeutic effect of ACE inhibitors in heart failure is primarily due to:

Accepted Answer

Reduction in preload and afterload via decreased angiotensin II

Answer

ACE inhibitors block conversion of angiotensin I to II, reducing vasoconstriction (afterload) and aldosterone-mediated sodium retention (preload).

Question 5

Which drug used for rheumatoid arthritis inhibits dihydrofolate reductase, requiring folate supplementation?

Accepted Answer

Methotrexate

Answer

Methotrexate inhibits dihydrofolate reductase, impairing nucleotide synthesis; folic acid supplementation reduces mucosal and hematologic side effects.

COMLEX-USA Practice Test

COMLEX-USA Practice Test

COMLEX-USA Pharmacology 3