NURS 6521
Advanced Pharmacology
Complete Midterms Review
(Questions & Solutions)
2025
1
,1. A 65‐year‐old patient with chronic heart failure is started on
intravenous furosemide. Thirty minutes later, he complains of
lightheadedness, and labs show serum potassium 3.0 mEq/L. Which
mechanism best explains his hypokalemia?
A. Blockade of Na⁺/K⁺‐ATPase in distal tubule
B. Increased distal tubular Na⁺ delivery enhancing K⁺ secretion
C. Direct inhibition of aldosterone release
D. Increased proximal reabsorption of K⁺
ANS: B
Rationale: Loop diuretics inhibit the Na⁺–K⁺–2Cl⁻ cotransporter in
the thick ascending limb, increasing Na⁺ delivery to the distal
nephron where Na⁺ reabsorption drives K⁺ secretion and urinary loss.
2. A 42‐year‐old woman on warfarin for a mechanical heart valve is
started on trimethoprim–sulfamethoxazole for a urinary tract
infection. Over the next week, her INR rises from 2.5 to 6.0. Which
interaction explains this change?
A. Trimethoprim induces CYP2C9, increasing warfarin clearance
B. Sulfamethoxazole displaces warfarin from albumin
C. Trimethoprim–sulfamethoxazole inhibits CYP2C9, reducing
warfarin metabolism
D. Sulfamethoxazole enhances vitamin K synthesis by gut flora
ANS: C
Rationale: Sulfamethoxazole (and trimethoprim) inhibit CYP2C9,
the main isoform metabolizing the more potent S‐warfarin
enantiomer, leading to elevated warfarin levels and increased INR.
3. A patient receives an infusion of the nondepolarizing
neuromuscular blocker vecuronium during surgery. Postoperatively,
2
, she has prolonged muscle weakness. Which drug reverses its effect
and by what mechanism?
A. Neostigmine—enhances acetylcholine by inhibiting
acetylcholinesterase
B. Atropine—blocks muscarinic receptors
C. Sugammadex—encapsulates vecuronium molecules
D. Physostigmine—antagonizes neuromuscular blockade directly
ANS: C
Rationale: Sugammadex forms a tight complex with steroidal
neuromuscular blockers (like vecuronium), removing them from the
neuromuscular junction and rapidly reversing blockade.
4. A 70‐year‐old man with atrial fibrillation is started on digoxin. One
week later, he reports anorexia, nausea, and sees yellow halos
around lights. His potassium is 3.2 mEq/L. Which action is most
appropriate?
A. Continue current dose; symptoms are common
B. Check serum digoxin level and correct hypokalemia
C. Increase potassium supplementation and double digoxin dose
D. Switch to dobutamine infusion
ANS: B
Rationale: Early digoxin toxicity presents with GI and visual
disturbances. Hypokalemia predisposes to toxicity. Measure digoxin
level and correct potassium before adjusting digoxin.
5. A 55‐year‐old woman with major depressive disorder is
transitioned from paroxetine to fluoxetine. She must discontinue
paroxetine before starting fluoxetine to avoid serotonin syndrome due
to fluoxetine’s:
A. Short half‐life
B. Active metabolite with long half‐life
3
Advanced Pharmacology
Complete Midterms Review
(Questions & Solutions)
2025
1
,1. A 65‐year‐old patient with chronic heart failure is started on
intravenous furosemide. Thirty minutes later, he complains of
lightheadedness, and labs show serum potassium 3.0 mEq/L. Which
mechanism best explains his hypokalemia?
A. Blockade of Na⁺/K⁺‐ATPase in distal tubule
B. Increased distal tubular Na⁺ delivery enhancing K⁺ secretion
C. Direct inhibition of aldosterone release
D. Increased proximal reabsorption of K⁺
ANS: B
Rationale: Loop diuretics inhibit the Na⁺–K⁺–2Cl⁻ cotransporter in
the thick ascending limb, increasing Na⁺ delivery to the distal
nephron where Na⁺ reabsorption drives K⁺ secretion and urinary loss.
2. A 42‐year‐old woman on warfarin for a mechanical heart valve is
started on trimethoprim–sulfamethoxazole for a urinary tract
infection. Over the next week, her INR rises from 2.5 to 6.0. Which
interaction explains this change?
A. Trimethoprim induces CYP2C9, increasing warfarin clearance
B. Sulfamethoxazole displaces warfarin from albumin
C. Trimethoprim–sulfamethoxazole inhibits CYP2C9, reducing
warfarin metabolism
D. Sulfamethoxazole enhances vitamin K synthesis by gut flora
ANS: C
Rationale: Sulfamethoxazole (and trimethoprim) inhibit CYP2C9,
the main isoform metabolizing the more potent S‐warfarin
enantiomer, leading to elevated warfarin levels and increased INR.
3. A patient receives an infusion of the nondepolarizing
neuromuscular blocker vecuronium during surgery. Postoperatively,
2
, she has prolonged muscle weakness. Which drug reverses its effect
and by what mechanism?
A. Neostigmine—enhances acetylcholine by inhibiting
acetylcholinesterase
B. Atropine—blocks muscarinic receptors
C. Sugammadex—encapsulates vecuronium molecules
D. Physostigmine—antagonizes neuromuscular blockade directly
ANS: C
Rationale: Sugammadex forms a tight complex with steroidal
neuromuscular blockers (like vecuronium), removing them from the
neuromuscular junction and rapidly reversing blockade.
4. A 70‐year‐old man with atrial fibrillation is started on digoxin. One
week later, he reports anorexia, nausea, and sees yellow halos
around lights. His potassium is 3.2 mEq/L. Which action is most
appropriate?
A. Continue current dose; symptoms are common
B. Check serum digoxin level and correct hypokalemia
C. Increase potassium supplementation and double digoxin dose
D. Switch to dobutamine infusion
ANS: B
Rationale: Early digoxin toxicity presents with GI and visual
disturbances. Hypokalemia predisposes to toxicity. Measure digoxin
level and correct potassium before adjusting digoxin.
5. A 55‐year‐old woman with major depressive disorder is
transitioned from paroxetine to fluoxetine. She must discontinue
paroxetine before starting fluoxetine to avoid serotonin syndrome due
to fluoxetine’s:
A. Short half‐life
B. Active metabolite with long half‐life
3
