Equivalent Dose Conversion: Spironolactone to Eplerenone

Dosing Equivalence

• The American College of Cardiology recommends that spironolactone 12.5-25 mg daily is equivalent to eplerenone 25 mg daily for initial dosing, and spironolactone 25 mg once or twice daily is equivalent to eplerenone 50 mg daily for maintenance dosing 1, 2, 3
• The American Heart Association guidelines suggest that for a patient taking spironolactone 25 mg daily, the target eplerenone dose is 50 mg daily 1

Conversion Protocol

• The American College of Cardiology recommends starting eplerenone at 25 mg daily for the first week, then increasing to 50 mg daily if potassium levels remain stable and renal function is stable 1, 2, 3
• For patients with reduced renal function, the maintenance dose of eplerenone may remain at 25 mg daily rather than 50 mg daily 1

Critical Monitoring Requirements

• The American College of Cardiology recommends checking potassium and creatinine levels within 3 days of starting eplerenone, and rechecking at 7 days after initiation 1, 2, 3
• The American Heart Association guidelines suggest monitoring potassium levels monthly for the first 3 months, then every 3 months thereafter 2, 3

Safety Thresholds

• The American College of Cardiology recommends not initiating eplerenone if baseline potassium levels are greater than 5.0 mEq/L 1, 2, 3
• The American Heart Association guidelines suggest holding or reducing the dose of eplerenone if potassium levels rise to 5.5-6.0 mEq/L 1

Potassium Management

• The American College of Cardiology recommends discontinuing all potassium supplements when switching between aldosterone antagonists, and counseling patients to avoid high-potassium foods during the transition 1, 2, 3, 5
• The American Heart Association guidelines suggest avoiding NSAIDs, which significantly increase hyperkalemia risk 1, 2, 3