I’m a 74‑year‑old man with type 2 diabetes and stage 3 chronic kidney disease (eGFR ≈ 50 mL/min/1.73 m²) currently taking metformin 2000 mg daily and empagliflozin (Jardiance) 25 mg daily—should I adjust these doses or change therapy?

Dose Adjustment Required for Metformin; Continue Empagliflozin

You should reduce your metformin dose to a maximum of 1000 mg daily (e.g., 500 mg twice daily) because your eGFR of approximately 50 mL/min/1.73 m² places you in the 45–59 range where dose reduction is recommended, while your empagliflozin (Jardiance) 25 mg should be continued unchanged for its critical cardiovascular and renal protective benefits. 1

Metformin Dose Adjustment Based on Your Kidney Function

For patients with eGFR 45–59 mL/min/1.73 m²:

• Reduce metformin to a maximum of 1000 mg per day (you are currently taking 2000 mg daily, which is too high for your kidney function). 1
• The dose reduction to 1000 mg daily (e.g., 500 mg twice daily or 1000 mg extended-release once daily) minimizes the risk of lactic acidosis while maintaining some glycemic benefit. 1
• Monitor your eGFR every 3–6 months (instead of annually) because you are now in a higher-risk category. 1

Critical threshold to remember:

• If your eGFR falls below 45 mL/min/1.73 m², metformin must be reduced by 50% (maximum 1000 mg daily). 1
• If your eGFR falls below 30 mL/min/1.73 m², metformin must be stopped completely—this is an absolute contraindication. 1

Empagliflozin (Jardiance) Should Continue Unchanged

Your empagliflozin 25 mg daily should NOT be reduced or stopped:

• Empagliflozin provides profound cardiovascular and renal protection at your current kidney function level (eGFR ≈ 50 mL/min/1.73 m²). 1, 2
• In the EMPA-REG OUTCOME trial, empagliflozin reduced incident or worsening nephropathy by 39% (HR 0.61; 95% CI 0.53–0.70), reduced doubling of serum creatinine by 44%, and reduced need for renal-replacement therapy by 55%. 2
• Empagliflozin slowed the annual eGFR decline from -1.46 mL/min/1.73 m²/year (placebo) to +0.23 mL/min/1.73 m²/year (empagliflozin), representing preservation rather than decline of kidney function. 3

Do not stop empagliflozin even if your eGFR falls below 45 mL/min/1.73 m²:

• Although glucose-lowering efficacy diminishes when eGFR < 45 mL/min/1.73 m², the cardiovascular and renal protective benefits persist. 1, 4, 5
• Empagliflozin can be continued down to eGFR ≥ 20 mL/min/1.73 m² for cardiorenal protection. 1, 4

Expected Initial eGFR Dip with Empagliflozin

You may experience a small, reversible drop in eGFR when continuing empagliflozin:

• An acute eGFR decline of 2–5 mL/min/1.73 m² typically occurs within the first 2–4 weeks, reflecting hemodynamic changes (reduced intraglomerular pressure) rather than kidney injury. 4, 3
• This initial dip is protective and should not prompt discontinuation of empagliflozin. 4, 3
• After the initial dip, eGFR stabilizes and the long-term decline is slower compared to placebo. 3

Additional Therapy if Glycemic Targets Are Not Met

If your blood sugar remains above target after reducing metformin:

• Add a GLP-1 receptor agonist (e.g., semaglutide, dulaglutide, or liraglutide) as the preferred third agent. 1
• GLP-1 receptor agonists provide additional cardiovascular protection, require no dose adjustment for kidney function, and have low hypoglycemia risk. 1
• Do not add a sulfonylurea (e.g., gliclazide, glipizide) because sulfonylureas lack cardiovascular and renal benefits and increase hypoglycemia risk, especially in CKD. 1, 4

Monitoring and Safety Precautions

Regular monitoring:

• Check eGFR every 3–6 months (not annually) because your kidney function is now in the 45–59 range. 1
• Monitor vitamin B12 levels if you have been on metformin for more than 4 years, as approximately 7% of long-term users develop deficiency. 1

Temporarily hold metformin (but not empagliflozin) during:

• Acute illness with reduced oral intake, fever, vomiting, or diarrhea. 6
• Hospitalization with high risk of acute kidney injury. 6
• Iodinated contrast imaging (hold metformin 48 hours before and after, then recheck eGFR before restarting). 6

Empagliflozin sick-day rules:

• Hold empagliflozin during acute illness with reduced oral intake, fever, vomiting, or diarrhea to prevent volume depletion and euglycemic diabetic ketoacidosis. 4, 7
• Stop empagliflozin at least 3 days before major surgery or procedures requiring prolonged fasting. 7

Common Pitfalls to Avoid

• Do not continue metformin 2000 mg daily with eGFR 45–59 mL/min/1.73 m²—this exceeds the safe dose and increases lactic acidosis risk. 1
• Do not stop empagliflozin when eGFR falls below 45 mL/min/1.73 m²—cardiovascular and renal benefits persist despite reduced glucose-lowering effect. 1, 4
• Do not discontinue empagliflozin because of the expected initial eGFR dip in the first 2–4 weeks—this is hemodynamic and protective, not harmful. 4, 3
• Do not add a sulfonylurea to replace the reduced metformin dose—GLP-1 receptor agonists are strongly preferred for additional glycemic control. 1, 4