Spironolactone Initiation Guidelines

Essential Pre-Treatment Laboratory Tests

The American Heart Association recommends measuring serum creatinine to ensure it meets safety thresholds: <2.5 mg/dL in men or <2.0 mg/dL in women 1, 2
The American Heart Association recommends calculating estimated glomerular filtration rate (eGFR) which must be >30 mL/min/1.73 m² 1, 2
In elderly patients or those with low muscle mass, direct measurement of eGFR or creatinine clearance is recommended by the American Heart Association 1
The European Society of Cardiology recommends checking serum potassium - must be <5.0 mEq/L before initiation 1, 2, 3

Spironolactone is potentially harmful and contraindicated when serum creatinine >2.5 mg/dL in men or >2.0 mg/dL in women, or eGFR <30 mL/min/1.73 m², or potassium >5.0 mEq/L, as stated by the American Heart Association 1, 2
The American Heart Association recommends discontinuing or reducing potassium supplements before starting spironolactone 1
Patients should be counseled to avoid potassium-containing salt substitutes and potassium-rich foods, as advised by the American Heart Association 1

The American Heart Association recommends rechecking potassium and renal function within 2-3 days after starting spironolactone, and repeating labs again at 7 days post-initiation 1
The European Society of Cardiology recommends monitoring at 1 week and 4 weeks after starting treatment 3, 4
Monthly monitoring for the first 3 months, then every 3 months thereafter, is recommended by the American Heart Association 1
After achieving maintenance dose, the European Society of Cardiology recommends monitoring at 1, 2, 3, and 6 months, then every 6 months 3, 4

The European Society of Cardiology notes that life-threatening hyperkalemia occurs more frequently in real-world practice than in clinical trials, especially in elderly patients 3, 4
Failure to verify baseline electrolytes and renal function before starting spironolactone can lead to serious adverse effects, as stated by the European Society of Cardiology 3, 4