Can empagliflozin be restarted in a post‑CAR‑T patient with serum creatinine 1.13 mg/dL (eGFR ~68 mL/min/1.73 m²) who is eating well and otherwise stable?

Can Empagliflozin Be Restarted in This Post-CAR-T Patient?

Yes, empagliflozin can be safely restarted at 10 mg once daily in this patient with serum creatinine 1.13 mg/dL (eGFR ~68 mL/min/1.73 m²) who is eating well and otherwise stable, as the eGFR is well above the minimum threshold of 20 mL/min/1.73 m² for initiation and the patient meets stability criteria. 1, 2

Pre-Restart Assessment

Before restarting empagliflozin, confirm the following:

• Verify eGFR ≥20 mL/min/1.73 m² – this patient's eGFR of 68 mL/min/1.73 m² exceeds the minimum threshold established by the 2023 ADA guidelines for cardiovascular and renal protection 1, 2
• Assess volume status – ensure the patient is euvolemic without signs of dehydration, hypotension, or orthostatic symptoms; correct any volume depletion before restarting 2, 3
• Confirm oral intake is adequate – the patient is eating well, which satisfies the requirement for normal food and fluid intake before resuming SGLT2 inhibitors 2
• Rule out acute illness – ensure no active infection, fever, vomiting, diarrhea, or other intercurrent illness that would contraindicate restart 2
• Review for recent nephrotoxic exposures – check for NSAIDs, contrast agents, or other nephrotoxins that could confound creatinine interpretation 3

Dosing and Administration

• Start empagliflozin 10 mg once daily – this is the standard evidence-based dose for cardiovascular and renal protection, with no titration required 2, 4
• No dose adjustment is needed at eGFR 68 mL/min/1.73 m² – full dosing is appropriate for both glycemic control and cardiorenal protection at this level of kidney function 2, 4

Expected Creatinine Changes After Restart

• Anticipate a transient eGFR dip of 2–5 mL/min/1.73 m² within the first 2–4 weeks, representing hemodynamic changes (reduced intraglomerular pressure) rather than true kidney injury 4, 3
• This acute decline should not prompt discontinuation – it is a reversible, expected effect that reflects the drug's renoprotective mechanism 3
• Recheck creatinine and eGFR 1–2 weeks after restart to document the expected dip and ensure stability 2, 3

Monitoring Strategy

• Measure serum creatinine and eGFR at 1–2 weeks post-restart to confirm the expected hemodynamic dip is modest (<30% rise in creatinine from baseline) 3
• Continue empagliflozin if creatinine rise is <30% and the patient remains euvolemic with stable clinical status 3
• Use BUN:creatinine ratio to differentiate hemodynamic changes (low ratio <10:1) from volume depletion (high ratio) if creatinine rises 3
• Consider urine microscopy if there is concern for true tubular injury, as it has excellent negative predictive value for excluding acute kidney injury 3

Medication Adjustments

• Review concurrent diuretics – consider reducing loop or thiazide diuretic doses temporarily to prevent excessive volume depletion, especially in elderly patients 2
• Continue ACE inhibitors or ARBs unchanged – these should not be withheld when restarting empagliflozin, as the combination provides additive renal protection 1, 4
• If on insulin or sulfonylureas, reduce doses by ~20% to mitigate hypoglycemia risk and monitor glucose closely for 2–4 weeks 2

Patient Education

• Reinforce sick-day rules – instruct the patient to hold empagliflozin during any acute illness with reduced oral intake, fever, vomiting, or diarrhea 2, 4
• Stop empagliflozin at least 3 days before major surgery or procedures requiring prolonged fasting to prevent postoperative ketoacidosis 2
• Warn about euglycemic diabetic ketoacidosis – advise immediate medical evaluation for unexplained malaise, nausea, vomiting, or abdominal pain even when blood glucose is normal 2, 4
• Counsel on genital mycotic infections – these occur in ~6% of SGLT2 inhibitor users versus 1% with placebo; emphasize daily hygiene 2

Common Pitfalls to Avoid

• Do not withhold empagliflozin solely because eGFR is <90 mL/min/1.73 m² – cardiovascular and renal benefits persist across the entire spectrum of kidney function down to eGFR 20 mL/min/1.73 m² 1, 2, 5
• Do not discontinue empagliflozin in response to the expected early eGFR dip – this hemodynamic change is reversible and does not indicate kidney injury 3
• Do not reduce the dose below 10 mg for cardiovascular or renal indications, even at lower eGFR levels – all outcome trials used the fixed 10 mg dose 2, 4

Evidence Supporting Restart at This eGFR Level

• The EMPA-KIDNEY trial enrolled patients with eGFR as low as 20 mL/min/1.73 m² and demonstrated a 28% reduction in progression of kidney disease or cardiovascular death (HR 0.72,95% CI 0.64–0.82) 5
• The EMPEROR-Reduced trial showed consistent cardiovascular and renal benefits across all eGFR subgroups, including patients with eGFR 20–30 mL/min/1.73 m² 6
• Empagliflozin slows eGFR decline by 1.11–2.41 mL/min/1.73 m²/year depending on baseline kidney function, with benefits independent of diabetes status 7, 6

Post-CAR-T Considerations

• CAR-T therapy does not contraindicate empagliflozin – the primary concerns are volume status, infection risk, and adequate oral intake, all of which appear stable in this patient 2
• Ensure no active cytokine release syndrome or immune effector cell-associated neurotoxicity syndrome – these would require holding empagliflozin until resolved 2