USMLE PRACTICE QUESTION OF THE WEEK

Question for October 10, 2025

A 74-year-old man with ischemic cardiomyopathy presents for follow-up. He reports persistent exertional fatigue but denies chest pain or syncope. Medications include lisinopril, carvedilol, furosemide, and spironolactone. He follows a low-sodium diet. BP is 114/70 mmHg, HR 64/min. Exam reveals bibasilar crackles and trace ankle edema. Jugular venous pressure is not elevated.

Laboratory results:
  • Potassium: 5.8 mEq/L (normal 3.5-5.0)
  • Creatinine: 2.3 mg/dL (baseline 1.2)
  • BUN: 42 mg/dL
Which of the following is the most appropriate next step in management?

Correct Answer:

C. Discontinue spironolactone

Correct Answer Explanation:

This patient with HFrEF has hyperkalemia and worsening kidney function while on spironolactone, a potassium-sparing diuretic. Although beneficial in reducing mortality, it is contraindicated in cases where K⁺ > 5.0 or creatinine > 2.0. Digoxin provides symptom control but does not improve survival. Sacubitril-valsartan is helpful in stable patients but not appropriate for uncontrolled hyperkalemia. Continuing the current regimen risks fatal arrhythmias.

Further Insight:

  • Spironolactone and eplerenone improve outcomes in HFrEF.
  • Use requires careful monitoring of potassium and renal function.