For patients with eGFR <30 mL/min/1.73 m², neither dapagliflozin nor empagliflozin should be initiated, but if already on treatment, both can be continued until dialysis—with dapagliflozin having slightly broader evidence down to eGFR 20 mL/min/1.73 m².
Current Guideline Thresholds for Initiation
Dapagliflozin can be initiated when eGFR ≥25 mL/min/1.73 m² for cardiovascular and renal protection, based on the DAPA-CKD trial which enrolled patients with eGFR 25–75 mL/min/1.73 m² 1, 2. The 2025 American Diabetes Association guidelines now support initiation at eGFR ≥20 mL/min/1.73 m² for patients with chronic kidney disease and albuminuria (UACR ≥200 mg/g), representing the most recent and permissive threshold 3.
Empagliflozin is recommended for initiation when eGFR ≥45 mL/min/1.73 m² according to older labeling 4, though the EMPA-KIDNEY trial enrolled participants down to eGFR 20 mL/min/1.73 m² and demonstrated consistent cardiovascular and renal benefits at very low eGFR levels 1.
For patients with eGFR <30 mL/min/1.73 m² who are not yet on an SGLT2 inhibitor, neither drug should be started 4, 1. However, if a patient is already receiving dapagliflozin or empagliflozin and eGFR subsequently falls below 25–30 mL/min/1.73 m², the drug may be continued at the standard 10 mg daily dose until dialysis is required 1, 3.
Evidence Quality and Trial Data
The DAPA-CKD trial (2020) is the single highest-quality study directly addressing this question, enrolling 4,304 participants with baseline eGFR 25–75 mL/min/1.73 m² and demonstrating that dapagliflozin reduced the composite of sustained eGFR decline ≥50%, end-stage kidney disease, or renal/cardiovascular death by 39% (HR 0.61,95% CI 0.51–0.72) 2. The kidney-specific composite outcome was reduced by 44% (HR 0.56,95% CI 0.45–0.68), and cardiovascular death or heart failure hospitalization by 29% (HR 0.71,95% CI 0.55–0.92) 2. These benefits were consistent regardless of diabetes status (67.5% had type 2 diabetes, 32.5% did not) 2.
Empagliflozin's evidence in advanced CKD comes from the EMPA-KIDNEY trial, which enrolled patients with eGFR down to 20 mL/min/1.73 m² and showed consistent cardiovascular and renal benefits 1. However, no head-to-head trial has directly compared dapagliflozin versus empagliflozin in patients with eGFR <30 mL/min/1.73 m² 5.
A 2021 retrospective study of 111 patients switching from dapagliflozin to empagliflozin (due to older eGFR restrictions) found that 70.3% maintained or improved glycemic control, with no significant change in renal function over 6 months 5. This suggests clinical interchangeability between the two agents when eGFR is 30–45 mL/min/1.73 m², though this study did not address the eGFR <30 population 5.
Practical Algorithm for eGFR <30 mL/min/1.73 m²
If the patient is NOT currently on an SGLT2 inhibitor:
- Do not initiate dapagliflozin or empagliflozin if eGFR is <25 mL/min/1.73 m² 4, 1.
- Consider dapagliflozin 10 mg daily if eGFR is 25–29 mL/min/1.73 m² AND UACR ≥200 mg/g, as this falls within the DAPA-CKD trial inclusion criteria 2, 1.
- Empagliflozin should not be initiated if eGFR is <45 mL/min/1.73 m² per older labeling, though newer evidence from EMPA-KIDNEY supports use down to eGFR 20 mL/min/1.73 m² 4, 1.
If the patient is ALREADY on dapagliflozin or empagliflozin:
- Continue the current SGLT2 inhibitor at 10 mg daily even if eGFR falls below 25–30 mL/min/1.73 m², until dialysis is required 1, 3.
- Do not discontinue the drug solely because eGFR has declined, as cardiovascular and renal protective benefits persist at lower eGFR levels despite loss of glycemic efficacy 1, 3.
If switching between agents is necessary (e.g., formulary restrictions):
- Dapagliflozin and empagliflozin are clinically interchangeable for cardiovascular and renal protection 6, 5.
- Switch directly from one to the other at the standard 10 mg daily dose without titration 1, 6.
Expected eGFR Changes and Monitoring
An acute, reversible eGFR decline of 2–5 mL/min/1.73 m² is expected within the first 2–4 weeks of initiating either dapagliflozin or empagliflozin 1, 7, 8. This hemodynamic dip reflects reduced intraglomerular pressure and should not prompt discontinuation 1, 7. A 2023 study of 51 non-diabetic CKD patients found that higher baseline eGFR predicted a larger initial dip, suggesting the effect is most pronounced in patients with residual glomerular hyperfiltration 7.
After the initial dip, eGFR stabilizes and the long-term decline is slower compared to placebo 9, 2. In the DAPA-CKD trial, dapagliflozin slowed chronic eGFR decline by 2.26 mL/min/1.73 m²/year in patients with diabetes and 1.29 mL/min/1.73 m²/year in those without diabetes 9.
Recheck eGFR 1–2 weeks after initiation, then every 3–6 months 1, 3. If eGFR decreases >30% from baseline AND there are signs of hypovolemia, reduce diuretic doses first before considering SGLT2 inhibitor adjustment 1.
Safety Considerations Specific to eGFR <30 mL/min/1.73 m²
Volume depletion risk is elevated in patients with advanced CKD, particularly those on concurrent loop diuretics or aged ≥75 years 1, 6. Assess volume status before initiation and consider temporary diuretic dose reduction 1, 3.
Genital mycotic infections occur in approximately 6% of SGLT2 inhibitor users versus 1% with placebo, and this risk is not significantly altered by eGFR level 1, 3.
Euglycemic diabetic ketoacidosis is rare but serious, and patients should be counseled to withhold the SGLT2 inhibitor during acute illness with reduced oral intake, fever, vomiting, or diarrhea, and to stop the drug at least 3 days before major surgery 1, 3.
Hyperkalemia risk is actually reduced with SGLT2 inhibitors, which may facilitate continued use of ACE inhibitors/ARBs or mineralocorticoid receptor antagonists in advanced CKD 1.
Common Pitfalls to Avoid
Do not discontinue dapagliflozin or empagliflozin when eGFR falls below 45 mL/min/1.73 m², as cardiovascular and renal benefits persist despite loss of glycemic efficacy 1, 3.
Do not stop the drug in response to the expected early eGFR dip in the first 2–4 weeks, as this change is hemodynamic and reversible, not indicative of kidney injury 1, 7.
Do not reduce the dose below 10 mg daily for cardiovascular or renal indications, even at lower eGFR levels, as all outcome trials used the fixed 10 mg dose 1, 3.
Do not withhold ACE inhibitors or ARBs when starting an SGLT2 inhibitor, as >99% of DAPA-CKD participants were on renin-angiotensin-aldosterone system blockers and the combination showed additive renal protection 1, 2.
Bottom Line for Clinical Practice
For eGFR <30 mL/min/1.73 m², dapagliflozin has slightly more robust evidence supporting initiation down to eGFR 20–25 mL/min/1.73 m² based on DAPA-CKD and updated 2025 ADA guidelines 1, 3, 2. Empagliflozin's labeling is more conservative (eGFR ≥45 mL/min/1.73 m² for initiation), though EMPA-KIDNEY data support use down to eGFR 20 mL/min/1.73 m² 4, 1. If a patient is already on either agent, continue it at 10 mg daily until dialysis, regardless of which drug was started first 1, 3. The choice between agents should be guided by formulary availability and cost, as they are clinically interchangeable for cardiovascular and renal protection 6, 5.