Repeated USMLE Questions Step 1 Review-161- Pharmacology

Q- A patient receiving amphotericin B develops fever, chills, and renal dysfunction. What is the primary mechanism of nephrotoxicity?

A- Afferent arteriole vasoconstriction

B- Autoimmune tubular injury

C- Direct glomerular inflammation

D- Inhibition of prostaglandin synthesis

A- Afferent arteriole vasoconstriction- Amphotericin B causes dose-dependent nephrotoxicity by constricting the afferent arteriole, reducing renal blood flow and GFR.

 

Q- A patient taking digoxin presents with nausea, confusion, and visual disturbances. Which electrolyte abnormality increases the risk of toxicity?

A- Hypercalcemia

B- Hyperkalemia

C- Hypocalcemia

D- Hypokalemia

D- Hypokalemia- Low potassium enhances digoxin binding to Na⁺/K⁺-ATPase, increasing the risk of arrhythmias and toxicity.

 

Q- Which medication is commonly associated with drug-induced lupus erythematosus?

A- Hydralazine

B- Methyldopa

C- Penicillamine

D- Propranolol

A- Hydralazine- Hydralazine can cause drug-induced lupus, especially in slow acetylators, presenting with arthralgia, fever, and positive ANA.

 

Q- A patient with peptic ulcer disease is prescribed misoprostol. What is the primary therapeutic effect of this drug?

A- Decreases gastric acid secretion

B- Increases gastric mucosal protection

C- Neutralizes gastric acid

D- Prevents Helicobacter pylori growth

B- Increases gastric mucosal protection- Misoprostol is a prostaglandin E₁ analog that increases mucus and bicarbonate secretion and improves mucosal blood flow.

 

Q- A patient on chronic steroid therapy abruptly stops the medication. Which complication is most likely?

A- Adrenal crisis

B- Cushing syndrome

C- Hyperaldosteronism

D- Thyroid storm

A- Adrenal crisis- Sudden withdrawal of long-term corticosteroids suppresses the HPA axis, leading to acute adrenal insufficiency.

 

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