Pharmacology Therapeutic Applications and Clinical Use 2 — Questions and Answers
Question 1: A patient with chronic heart failure is prescribed digoxin. Which serum electrolyte must be closely monitored to prevent digoxin toxicity?
- Sodium
- Potassium (Correct answer)
- Calcium
- Phosphorus
Correct answer: Potassium
Hypokalemia potentiates digoxin toxicity by increasing drug binding to Na+/K+-ATPase.
Question 2: Metformin is contraindicated in a patient with an eGFR below 30 mL/min/1.73m² primarily because of the risk of:
- Hypoglycemia
- Lactic acidosis (Correct answer)
- Pancreatitis
- Agranulocytosis
Correct answer: Lactic acidosis
Reduced renal clearance causes metformin accumulation, leading to lactic acidosis risk.
Question 3: Which of the following is the first-line pharmacological treatment for uncomplicated hypertension in a Black, non-diabetic patient according to JNC guidelines?
- ACE inhibitor
- Beta-blocker
- Thiazide diuretic or calcium channel blocker (Correct answer)
- ARB
Correct answer: Thiazide diuretic or calcium channel blocker
Thiazide diuretics and CCBs are preferred first-line agents in Black patients due to greater efficacy.
Question 4: A patient taking warfarin starts a course of fluconazole. What clinical adjustment is most likely needed?
- Increase warfarin dose
- Decrease warfarin dose (Correct answer)
- Discontinue warfarin
- No adjustment needed
Correct answer: Decrease warfarin dose
Fluconazole inhibits CYP2C9, reducing warfarin metabolism and increasing anticoagulant effect.
Question 5: Sublingual nitroglycerin is used in acute angina attacks primarily because this route:
- Avoids first-pass metabolism (Correct answer)
- Increases bioavailability via enterohepatic circulation
- Slows absorption for sustained effect
- Reduces GI side effects
Correct answer: Avoids first-pass metabolism
The sublingual route delivers nitroglycerin directly into systemic circulation, bypassing hepatic first-pass metabolism.
Question 6: Which drug class is used as first-line therapy for acute gout flares due to its anti-inflammatory mechanism targeting neutrophil function?
- Allopurinol
- Probenecid
- Colchicine (Correct answer)
- Febuxostat
Correct answer: Colchicine
Colchicine inhibits microtubule polymerization, impairing neutrophil migration and phagocytosis in gouty joints.
Question 7: A patient with GERD unresponsive to antacids is started on omeprazole. Its mechanism involves irreversible inhibition of:
- Histamine H2 receptors
- Gastrin receptors
- H+/K+-ATPase proton pump (Correct answer)
- Muscarinic M1 receptors
Correct answer: H+/K+-ATPase proton pump
Omeprazole, a PPI, covalently inhibits the H+/K+-ATPase enzyme on parietal cells, suppressing acid secretion.
Pharmacology Therapeutic Applications and Clinical Use 2
A patient with chronic heart failure is prescribed digoxin.
Which serum electrolyte must be closely monitored to prevent digoxin toxicity?