Are mineralocorticoids contraindicated in patients with an estimated Glomerular Filtration Rate (eGFR) of less than 20?

Mineralocorticoid Receptor Antagonists in Patients with eGFR <20 ml/min/1.73 m²

Mineralocorticoid receptor antagonists (MRAs) are contraindicated in patients with an eGFR less than 20 ml/min/1.73 m², particularly nonsteroidal MRAs which should only be used when eGFR is >25 ml/min/1.73 m². 1

Evidence-Based Recommendations by MRA Type

Nonsteroidal MRAs (e.g., Finerenone)

• Nonsteroidal MRAs should only be used in patients with eGFR >25 ml/min/1.73 m² according to the 2024 KDIGO guidelines 1
• These agents are specifically indicated for adults with type 2 diabetes who are at high risk of CKD progression and cardiovascular events with persistent albuminuria despite standard therapies 1
• Normal serum potassium concentration is a prerequisite for initiating therapy 1

Steroidal MRAs (e.g., Spironolactone, Eplerenone)

• Steroidal MRAs are primarily indicated for heart failure, hyperaldosteronism, or refractory hypertension 1
• These agents carry significant risk of hyperkalemia and reversible decline in glomerular filtration, particularly in patients with low GFR 1
• According to heart failure guidelines, steroidal MRAs should be used only when eGFR is >30 ml/min/1.73 m² 1

Risks and Monitoring

Hyperkalemia Risk

• The risk of hyperkalemia increases substantially with declining kidney function 1
• Regular monitoring of serum potassium is essential after MRA initiation 1
• Patient selection should prioritize those with consistently normal serum potassium levels 1

Renal Function Considerations

• MRAs may cause a reversible decline in GFR, which should be distinguished from progressive kidney disease 1, 2
• The initial temporary decrease in eGFR with MRA treatment may reflect correction of glomerular hyperfiltration rather than true kidney injury 2
• Despite this initial decline, long-term kidney and cardiovascular benefits may still occur in appropriate patients 2

Special Circumstances

Heart Failure Patients

• Recent research suggests that patients with heart failure may still benefit from MRAs even with severe kidney disease 3
• In heart failure patients who experience a decline in eGFR to <30 ml/min/1.73 m² while on MRA therapy, the absolute risk reduction for cardiovascular events may outweigh the increased risk of hyperkalemia 3
• However, this does not override the contraindication for initiating MRAs in patients with baseline eGFR <20 ml/min/1.73 m² 1

Practical Management

When to Avoid MRAs

• Avoid initiating MRAs in patients with eGFR <20 ml/min/1.73 m² 1
• Avoid use in patients with uncontrolled hyperkalemia (K+ >5.5 mmol/L) 1
• Consider alternative therapies such as SGLT2 inhibitors which can be used down to eGFR of 20 ml/min/1.73 m² 1

When to Discontinue Existing MRA Therapy

• Consider discontinuing MRAs if serum potassium rises above 6.0 mmol/L despite medical management 1
• Consider dose reduction or discontinuation if there is symptomatic hypotension or uncontrolled hyperkalemia 1
• If eGFR falls below 20 ml/min/1.73 m², reassess risk-benefit ratio with particular caution 1

Alternative Therapies for CKD Management

• SGLT2 inhibitors are recommended for patients with eGFR ≥20 ml/min/1.73 m² and can be continued even if eGFR falls below 20 ml/min/1.73 m² unless not tolerated 1
• RAS inhibitors (ACEi or ARB) can be continued even when eGFR falls below 30 ml/min/1.73 m² 1
• GLP-1 receptor agonists may be considered for cardiovascular risk reduction in patients with low eGFR 1