What is the best next step in managing a patient with hyperkalemia, impaired renal function, and heart failure with reduced ejection fraction who is currently on furosemide (Lasix) and spironolactone (Aldactone)?

Management of Hyperkalemia in a Patient with Heart Failure and Chronic Kidney Disease

The best next step in this patient with hyperkalemia (potassium 5.9 mEq/L), impaired renal function (eGFR 26), and heart failure with reduced ejection fraction is to discontinue spironolactone while maintaining other guideline-directed medical therapy.

Assessment of the Current Situation

This 74-year-old woman presents with:

• Heart failure with reduced ejection fraction (HFrEF)
• Chronic kidney disease (CKD) with eGFR 26 ml/min/1.73m²
• Hyperkalemia (potassium 5.9 mEq/L)
• Current medications: furosemide, spironolactone, empagliflozin, and dapagliflozin
• Euvolemic status

Rationale for Discontinuing Spironolactone

1. Severity of hyperkalemia: A potassium level of 5.9 mEq/L represents significant hyperkalemia that requires immediate intervention 1.

2. Medication review: Spironolactone is a potassium-sparing diuretic that directly contributes to hyperkalemia, especially in patients with impaired renal function 2. The FDA label for spironolactone specifically warns about increased hyperkalemia risk with impaired renal function 2.

3. Renal function: With an eGFR of 26 ml/min/1.73m², this patient has significantly impaired renal function, which increases the risk of spironolactone-induced hyperkalemia 3.

4. Drug interactions: The combination of spironolactone with other RAAS inhibitors (like empagliflozin) further increases hyperkalemia risk 3.

Management Algorithm

1. Immediate action:

   • Discontinue spironolactone 3, 2
   • Maintain other guideline-directed medical therapy including furosemide and SGLT2 inhibitors

2. Monitoring:

   • Recheck potassium and renal function within 2-3 days 1
   • Continue monitoring monthly for at least 3 months

3. Medication optimization:

   • Continue furosemide to promote potassium excretion
   • Maintain SGLT2 inhibitors as they provide cardiovascular benefit and may help reduce hyperkalemia risk 1

4. If hyperkalemia persists:

   • Consider potassium binders (patiromer or sodium zirconium cyclosilicate) 1
   • Adjust furosemide dosing to enhance potassium excretion

Why Other Options Are Not Preferred

• Adding sodium bicarbonate: While this can help in metabolic acidosis, it's not the first-line treatment for hyperkalemia in this context and doesn't address the primary cause 4.

• Continuing current regimen: Maintaining spironolactone with this degree of hyperkalemia and renal dysfunction poses significant cardiac risk 3.

Important Considerations

• Balancing GDMT and safety: While mineralocorticoid receptor antagonists like spironolactone provide mortality benefit in HFrEF, the risk of severe hyperkalemia in this patient with advanced CKD outweighs the benefit 3.

• Monitoring requirements: According to guidelines, when potassium rises above 5.5 mEq/L, spironolactone should be discontinued immediately and blood chemistry monitored closely 3.

• Alternative strategies: After potassium normalizes, consider whether the patient might benefit from a lower dose of spironolactone (e.g., 25 mg on alternate days) with very close monitoring, or whether other GDMT medications should be optimized instead 3.

By discontinuing spironolactone while maintaining other heart failure medications, you address the immediate risk of hyperkalemia while preserving as much guideline-directed medical therapy as safely possible for this patient with both heart failure and advanced kidney disease.