CKD: ACEi/ARB, SGLT2, Finerenone — When & How

Chronic kidney disease (CKD) care is about slowing decline, protecting the heart, and avoiding treatment landmines. This is a pragmatic sequence for ACEi/ARB, SGLT2 inhibitors, and finerenone, with monitoring rules that keep patients safe.

Stage & Risk First

• eGFR (G1–G5) and albuminuria (A1 <30, A2 30–300, A3 >300 mg/g) determine risk.
• BP target: many adults with albuminuria benefit from ~≤130/80 mmHg if tolerated; use home/ambulatory data when possible.
• Baseline labs: BMP (Cr/K⁺/HCO₃⁻), ACR (urine albumin/creatinine), lipids, HbA1c in diabetes.

1) Start an ACEi or ARB (never both)

• Who: Hypertension with CKD (especially A2/A3) or diabetes with albuminuria. Also consider in normotensive A3 with diabetes for renoprotection.
• How: Begin low; recheck Cr and K⁺ in 1–2 weeks. A creatinine rise up to ~30% can be acceptable—evaluate volume status, NSAIDs, and renal artery stenosis if higher.
• Avoid dual blockade (ACEi+ARB)—higher hyperkalemia/AKI risk without outcome gain.
• Contraindications: pregnancy, history of angioedema (ACEi), bilateral renal artery stenosis (relative), K⁺ >5.5 uncontrolled.

2) Add an SGLT2 Inhibitor (if eligible)

• Who: Type 2 diabetes with CKD and albuminuria; growing use in non-diabetic CKD with albuminuria (follow local guidance and eGFR cutoffs).
• eGFR thresholds: Initiation allowed down to low eGFR ranges per product label; glycemic effect wanes as eGFR falls, but kidney/heart benefits persist.
• Practical tips: Expect a small, early dip in eGFR (“hemodynamic dip”) that stabilizes—continue unless excessive. Hold during acute illness/volume depletion (“sick-day” rule).
• Adverse effects: genital mycotic infections (hygiene counseling), rare euglycemic DKA in insulin users—educate on signs.

3) Consider Finerenone (non-steroidal MRA) in T2D with Albuminuria

• Who: Type 2 diabetes, CKD with persistent A2/A3 albuminuria despite maximized ACEi/ARB.
• Before starting: Ensure K⁺ ≤5.0 mEq/L and stable renal function. Check drug interactions (CYP3A4).
• Dosing concept: Dose is guided by eGFR and serum K⁺; up-titrate if K⁺ remains ≤4.8–5.0. Down-titrate/hold if K⁺ rises.
• Why finerenone vs spironolactone: designed for cardiorenal protection with lower anti-androgen side effects; still monitor K⁺ closely.

Hyperkalemia: Prevent and Manage

• Target K⁺ roughly 4.0–5.0. Review diet, stop potassium supplements, and avoid NSAIDs where possible.
• Use loop or thiazide diuretics for volume/BP and to offset K⁺ rise when appropriate.
• Newer potassium binders (as locally available) can permit continuation of ACEi/ARB/MRA when otherwise beneficial.

Metabolic Acidosis & Bone–Mineral Basics

• Serum bicarbonate <22 mEq/L: consider oral sodium bicarbonate to target normal range if not fluid-overloaded.
• Assess phosphate, calcium, vitamin D, and PTH in advanced CKD; manage phosphate load and vitamin D deficiency per guidance.

Diabetes & Lipids

• Aim for individualized A1c; avoid hypoglycemia as eGFR falls (insulin and sulfonylureas last longer).
• Statin therapy for most adults with CKD not on dialysis; consider ezetimibe add-on if high risk.

Diet & Lifestyle Foundations

• Sodium: practical limit (e.g., ~2 g/day) to aid BP and edema control.
• Protein: moderate intake; align with nutrition guidance in CKD rather than high-protein fad diets.
• Exercise, smoking cessation, vaccination (influenza, pneumococcal, hepatitis B when indicated).

Monitoring Timeline (rule of thumb)

• After any ACEi/ARB/MRA/SGLT2 start or dose change: check Cr, K⁺ in 1–2 weeks, then 4–12 weeks, then every 3–6 months based on stability.
• Track ACR every 3–12 months to gauge renoprotection response.
• Reinforce “sick-day” plan: hold nephrotoxic meds and SGLT2 during dehydration/acute illness; restart when eating/drinking normally.

When to Image or Refer

• Rapid eGFR decline, refractory hypertension, suspected renal artery stenosis, hematuria with RBC casts, or unclear etiology.
• Consider nephrology referral for eGFR <30 (G4–G5), persistent A3 albuminuria, recurrent hyperkalemia/metabolic complications, or diagnostic uncertainty.
• Early discussion of kidney replacement options when trajectory suggests progression (transplant evaluation, access planning).

Medication Landmines

• Avoid routine NSAIDs; review OTCs/supplements (nephrotoxins are common).
• Contrast studies: use indications-based protocols, hydrate, and coordinate with radiology for high-risk patients.
• Dose-adjust renally cleared drugs (metformin thresholds, antibiotics, DOAC dosing by CrCl, etc.).

Patient FAQs

“My creatinine went up after ACEi—should I stop?” A small rise (up to ~30%) can be expected and often acceptable; your clinician will recheck and look for reversible causes like dehydration or NSAIDs.

“Can I take painkillers?” Prefer acetaminophen. Avoid routine NSAIDs; discuss alternatives if pain is chronic.

References & Notes

Practical CKD sequence emphasizing RAAS blockade, SGLT2 inhibitors, and finerenone in appropriate patients, with close K⁺/creatinine monitoring and attention to sick-day rules. Local labels and protocols vary—follow regional guidance. Educational only.