What are the implications of a reduced estimated Glomerular Filtration Rate (eGFR) from 68 to 61 on my current medication regimen, including Empagliflozin (Empagliflozin), Metformin (Metformin), and Losartan (Losartan)?

Managing Medications with Reduced eGFR from 68 to 61

A decrease in eGFR from 68 to 61 mL/min/1.73 m² does not require any medication adjustments for your current regimen of empagliflozin, metformin, and losartan, as this level remains above the critical threshold of 45 mL/min/1.73 m² where medication changes would be necessary.

Impact on Current Medications

Metformin

• No dosage adjustment is needed for metformin at an eGFR of 61 mL/min/1.73 m² 1
• FDA guidance states that metformin benefits and risks should only be reassessed when eGFR falls below 45 mL/min/1.73 m² 1
• Continue monitoring renal function regularly while taking metformin 1
• Temporary discontinuation of metformin is only required during iodinated contrast procedures if eGFR is 30-60 mL/min/1.73 m² 1

Empagliflozin (SGLT2 inhibitor)

• No dosage adjustment is required for empagliflozin at an eGFR of 61 mL/min/1.73 m² 1, 2
• Empagliflozin remains effective for glycemic control at this level of renal function 2
• The drug actually provides renal protection and slows CKD progression at this eGFR level 1, 3
• Pharmacokinetic data shows only modest increases in drug exposure with mild renal impairment (eGFR 60-90 mL/min/1.73 m²), which does not warrant dose adjustment 4, 5

Losartan (ARB)

• No dosage adjustment is needed for losartan at an eGFR of 61 mL/min/1.73 m² 1
• ARBs like losartan are recommended as first-line therapy for hypertension when albuminuria is present 1
• Continued use of losartan provides renoprotective effects that may help prevent further eGFR decline 1

Monitoring Recommendations

• Regular monitoring of kidney function is essential to track any further decline in eGFR 1
• Monitor for signs of volume depletion, especially if taking both an SGLT2 inhibitor and an ARB 6
• Be vigilant for any symptoms of urinary tract infections or genital mycotic infections, which can occur with SGLT2 inhibitors 6
• If eGFR continues to decline and approaches 45 mL/min/1.73 m², prepare for potential medication adjustments, particularly for metformin 1

Clinical Significance of eGFR Change

• A decrease from 68 to 61 mL/min/1.73 m² represents a mild decline but remains in the mild CKD range (eGFR 60-89 mL/min/1.73 m²) 1
• This level of decline may be within normal variability or represent early progression of kidney disease 1
• SGLT2 inhibitors like empagliflozin can cause an initial small decline in eGFR (2-5 mL/min/1.73 m²) that typically stabilizes and is associated with long-term kidney protection 7
• The combination of empagliflozin and losartan is particularly beneficial for kidney protection in patients with diabetes 1

Action Thresholds for Future eGFR Changes

• If eGFR falls below 45 mL/min/1.73 m²: Reassess metformin risks/benefits 1
• If eGFR falls below 30 mL/min/1.73 m²: Discontinue metformin 1
• If eGFR falls below 20 mL/min/1.73 m²: Consider discontinuing empagliflozin as its glycemic efficacy is significantly reduced, though cardiovascular benefits may persist 1, 8

Common Pitfalls to Avoid

• Don't discontinue medications prematurely based on small eGFR fluctuations; the current change does not warrant medication adjustments 1
• Avoid attributing all eGFR changes to medication effects; natural disease progression, dehydration, or measurement variability can all affect eGFR 1
• Don't overlook the renoprotective benefits of SGLT2 inhibitors due to concerns about mild eGFR decline; these medications provide long-term kidney protection despite initial small decreases in eGFR 1, 3