Can I start finerenone (finerenone) in a male patient with type 2 diabetes mellitus (T2DM) and nephrotic range proteinuria with impaired renal function (creatinine level of 1.43)?

Can You Start Finerenone in This Patient?

Yes, you can start finerenone in this male patient with T2DM, nephrotic-range proteinuria, and creatinine 1.43 mg/dL, provided his eGFR is ≥25 mL/min/1.73 m² and serum potassium is ≤4.8 mmol/L. 1

Critical Pre-Initiation Requirements

Before starting finerenone, you must verify three essential criteria:

• Calculate the eGFR - A creatinine of 1.43 mg/dL in a male typically corresponds to an eGFR of approximately 50-60 mL/min/1.73 m² (depending on age and race), which falls within the approved range of ≥25 mL/min/1.73 m² 1
• Check serum potassium - Must be ≤4.8 mmol/L before initiation, as higher baseline potassium increases hyperkalemia risk unacceptably 1, 2
• Confirm maximum tolerated RAS inhibitor therapy - Patient must already be on an ACE inhibitor or ARB at the highest tolerated dose, as finerenone is add-on therapy, not first-line 2, 1

Dosing Algorithm for This Patient

Start with 10 mg once daily if the eGFR is 25-60 mL/min/1.73 m² (most likely scenario given creatinine 1.43) 1

• After 1 month, uptitrate to 20 mg daily if serum potassium remains ≤4.8 mmol/L and eGFR is stable 1
• If eGFR is >60 mL/min/1.73 m², start with 20 mg once daily 1

Evidence Supporting Use in Nephrotic-Range Proteinuria

The landmark trials (FIDELIO-DKD and FIGARO-DKD) specifically enrolled patients with substantial albuminuria, including those with nephrotic-range proteinuria:

• FIDELIO-DKD enrolled patients with UACR 300-5,000 mg/g (mean albuminuria >900 mg/day), demonstrating a 36% reduction in progression to end-stage kidney disease 2, 1
• Real-world data confirms safety and efficacy in patients with nephrotic syndrome and DKD, showing decreased urinary protein-creatinine ratio without increasing serum potassium levels 3
• Albuminuria reduction mediates outcomes - 84% of finerenone's kidney protective effect is mediated through early albuminuria reduction, making it particularly valuable in nephrotic-range proteinuria 4

Treatment Sequencing Priority

The 2024 ADA and 2022 KDIGO guidelines establish a clear hierarchy:

1. First-line foundation: Maximum tolerated ACE inhibitor or ARB 2
2. Second-line priority: SGLT2 inhibitor (if eGFR ≥20 mL/min/1.73 m²) for superior kidney and cardiovascular protection 2
3. Third-line consideration: Finerenone for persistent albuminuria despite SGLT2 inhibitor, or if SGLT2i is not tolerated 2, 1

If this patient is not yet on an SGLT2 inhibitor, prioritize adding that first before or concurrently with finerenone, as SGLT2 inhibitors provide larger absolute risk reductions and may reduce hyperkalemia risk when combined with finerenone 2, 5

Potassium Monitoring Protocol

Hyperkalemia is the primary safety concern, occurring in 14% vs 6.9% with placebo, but permanent discontinuation remains rare (1.7% vs 0.6%) 1:

• Before initiation: Verify potassium ≤4.8 mmol/L 1
• At 1 month: Recheck potassium to capture the predictable initial rise 1
• Every 4 months thereafter: Ongoing monitoring during maintenance therapy 1

Management thresholds:

• Potassium ≤4.8 mmol/L: Continue current dose and proceed with uptitration if applicable 1
• Potassium 4.9-5.5 mmol/L: Continue finerenone without dose adjustment, maintain monitoring 1
• Potassium >5.5 mmol/L: Immediately hold finerenone, address dietary potassium and concomitant medications, restart at 10 mg daily when potassium returns to ≤5.0 mmol/L 1

Expected Clinical Benefits in This Patient

Given nephrotic-range proteinuria, this patient is at extremely high risk for both kidney failure and cardiovascular events. Finerenone provides:

• 18% reduction in kidney composite outcomes (kidney failure, sustained ≥40% eGFR decrease, or kidney death) 1
• 14% reduction in cardiovascular composite outcomes (CV death, nonfatal MI, nonfatal stroke, heart failure hospitalization) 1
• Substantial proteinuria reduction - dose-dependent UACR reduction, with 10 mg showing a 24% placebo-corrected reduction and 20 mg showing a 38% reduction 6

Common Pitfalls to Avoid

• Do not initiate finerenone without first optimizing RAS inhibitor therapy - this is foundational and non-negotiable 2, 1
• Do not permanently discontinue for a single hyperkalemia episode >5.5 mmol/L - temporary interruption with dose reduction upon restart successfully manages most cases 1
• Do not delay SGLT2 inhibitor initiation - these agents provide complementary mechanisms and may be additive with finerenone 2, 5
• Do not ignore blood pressure optimization - verify BP is at target (<130/80 mm Hg) as part of comprehensive DKD management 2

Contraindications That Would Preclude Use

Do not start finerenone if:

• eGFR <25 mL/min/1.73 m² (no safety or efficacy data in this population) 1
• Patient is on dialysis or has ESRD 1
• Baseline potassium >4.8 mmol/L 1
• Not on maximum tolerated RAS inhibitor 2, 1