Should I initiate finerenone (Kerendia) in a patient with left ventricular ejection fraction 50-55%, estimated glomerular filtration rate 40 mL/min/1.73 m², serum potassium ≤4.8 mmol/L, who is already on a maximally tolerated ACE inhibitor or ARB?

Should You Initiate Finerenone (Kerendia) in This Patient?

Yes, initiate finerenone 10 mg once daily in this patient with EF 50-55%, eGFR 40 mL/min/1.73 m², and potassium ≤4.8 mmol/L who is already on maximally tolerated ACE inhibitor or ARB, provided the patient has type 2 diabetes and persistent albuminuria (UACR ≥30 mg/g). 1, 2

Critical Eligibility Criteria

Before initiating finerenone, verify the following requirements are met:

• Type 2 diabetes with chronic kidney disease (finerenone is FDA-approved only for diabetic CKD, not non-diabetic CKD) 1, 2
• Persistent albuminuria ≥30 mg/g despite maximally tolerated RAS inhibitor therapy 1, 2
• eGFR ≥25 mL/min/1.73 m² (your patient's eGFR of 40 meets this threshold) 1, 2
• Serum potassium ≤4.8 mmol/L at baseline 1, 2
• Maximally tolerated dose of ACE inhibitor or ARB already established 1, 2

Ejection Fraction Considerations

Your patient's EF of 50-55% falls into the HFpEF/HFmrEF range, which is relevant for finerenone use:

• KDIGO 2022 and ADA 2024 guidelines recommend finerenone for patients with type 2 diabetes and CKD with persistent albuminuria, regardless of heart failure status 1
• Recent FINEARTS-HF trial data (2025) demonstrated finerenone reduces cardiovascular death and total heart failure events in patients with EF ≥40%, with consistent benefits across the spectrum of kidney function 3, 4
• The DCRM 2.0 guidelines specifically recommend finerenone for HFpEF (EF ≥50%) and HFmrEF (EF 41-49%) patients with comorbid CKD 1

Treatment Sequencing: Where Does Finerenone Fit?

The optimal treatment hierarchy for diabetic CKD is:

1. First-line foundation: Maximally tolerated ACE inhibitor or ARB 1, 2
2. Second-line priority: SGLT2 inhibitor (larger effect size on kidney and cardiovascular outcomes) 1
3. Third-line consideration: Finerenone for persistent albuminuria despite above therapies, or if SGLT2i intolerance 1, 2

Important nuance: While SGLT2 inhibitors are preferred as second-line therapy, finerenone can be added to SGLT2 inhibitors (triple therapy with RAS inhibitor + SGLT2i + finerenone appears promising and may reduce hyperkalemia risk) 5, 6

Dosing Protocol for Your Patient

Start finerenone 10 mg once daily because the patient's eGFR is 40 mL/min/1.73 m² (in the 25-60 range) 1, 2, 7

Dose Titration After 1 Month:

• Increase to 20 mg once daily if: 1, 2, 7
  • Serum potassium remains ≤4.8 mmol/L
  • eGFR is stable (no clinically significant decline)
  • Medication is well-tolerated

Monitoring Requirements

Potassium Monitoring Schedule:

• Pre-initiation: Confirm potassium ≤4.8 mmol/L 2, 7, 8
• At 1 month: Check potassium to assess for early rise 2, 7, 8
• Every 4 months thereafter during maintenance therapy 2, 7, 8

Potassium-Based Management Algorithm:

Potassium Level	Action
≤4.8 mmol/L	Continue current dose; monitor every 4 months [2,7,8]
4.9-5.5 mmol/L	Continue current dose; maintain monitoring every 4 months [2,7,8]
>5.5 mmol/L	Hold finerenone immediately; correct dietary potassium, review concomitant medications, recheck potassium [2,7,8]
≤5.0 mmol/L (after holding)	Restart at 10 mg daily [2,7,8]

Additional Monitoring:

• eGFR: Baseline, 1 month, then every 4 months 2, 7
• UACR: Baseline and month 4 to assess albuminuria response 2, 7

Expected Creatinine Changes: Do Not Discontinue Prematurely

A serum creatinine rise up to 30% from baseline is expected and reflects beneficial hemodynamic effects, not acute kidney injury 7

• This mirrors the pattern seen with ACE inhibitors and ARBs 7
• The early eGFR decline (≈2.9 mL/min/1.73 m²) reflects reduced intraglomerular pressure, not true renal injury 7
• Continue finerenone if creatinine rise is <30% and patient is clinically stable without volume depletion or nephrotoxin exposure 7
• Temporarily hold only if creatinine increase exceeds 30%, or if volume depletion, hypotension, or acute illness is present 7

Clinical Benefits Your Patient Can Expect

Kidney Protection:

• 18% reduction in composite kidney outcomes (kidney failure, sustained ≥40% eGFR decrease, or kidney death) 1
• 36% reduction in progression to end-stage kidney disease 1
• Substantial albuminuria reduction (median 73% decrease in real-world Chinese cohort at 6 months) 6

Cardiovascular Protection:

• 14% reduction in composite cardiovascular outcomes (CV death, nonfatal MI, nonfatal stroke, heart failure hospitalization) 1
• 13% reduction in cardiovascular events in FIGARO-DKD trial 7
• Benefits consistent across the spectrum of kidney function in heart failure patients 3, 4

Safety Profile and Hyperkalemia Risk

• Hyperkalemia occurred in 14% vs 6.9% with placebo in pooled trial data 7
• Permanent discontinuation due to hyperkalemia was rare (1.7% vs 0.6% placebo) 7
• No deaths from hyperkalemia over 3 years of follow-up 7
• Real-world data from China showed only 2.4% discontinued due to hyperkalemia 6

Risk Factors for Hyperkalemia:

• Lower eGFR (particularly <45 mL/min/1.73 m²) 7
• Beta-blocker use 7
• Concomitant potassium supplements or potassium-sparing diuretics 8

Protective Factors:

• SGLT2 inhibitor co-administration reduces hyperkalemia risk 7, 5, 6
• Triple therapy (RAS inhibitor + SGLT2i + finerenone) appears to be a promising strategy for reducing hyperkalemia while maximizing albuminuria reduction 5, 6

Common Pitfalls to Avoid

• Do not discontinue finerenone for a single potassium reading >5.5 mmol/L; temporarily hold, correct potassium, and restart at 10 mg daily once potassium ≤5.0 mmol/L 2, 7, 8
• Do not mistake hemodynamic creatinine changes for AKI; creatinine rises up to 30% are expected and beneficial 7
• Do not use finerenone as monotherapy; it must be added only after maximally tolerated ACE/ARB 2, 7
• Do not underdose out of fear of side effects; pivotal trials used maximally tolerated doses (10-20 mg daily, adjusted for eGFR) 7
• Do not initiate if baseline potassium >4.8 mmol/L or eGFR <25 mL/min/1.73 m² 2, 7, 8

Contraindications

Absolute contraindications:

• eGFR <25 mL/min/1.73 m² or end-stage renal disease 2, 7, 8
• Baseline serum potassium >4.8 mmol/L 2, 7, 8

Relative contraindications (trial exclusion criteria):

• Uncontrolled hypertension 7
• Concomitant use of ACE inhibitor + ARB (dual RAS blockade is potentially harmful) 8

When to Refer to Nephrology

Consider nephrology referral if: 1

• eGFR falls below 30 mL/min/1.73 m² (stage 4 CKD) for discussion of renal replacement therapy
• Creatinine rise >30% from baseline fails to stabilize after holding potential offending agents 7
• Persistent hyperkalemia despite dietary modification and medication adjustment
• Uncertainty about etiology of kidney disease or difficult management issues 1