Can You Start Farxiga on This Patient?
No, you should not start Farxiga (dapagliflozin) for glycemic control in this patient with HbA1c 6.0% and eGFR 38 mL/min/1.73 m², but you may consider it for renoprotection if the patient has diabetes with albuminuria or other cardiovascular indications.
Rationale for Glycemic Control Indication
HbA1c Target Concerns
This patient's HbA1c of 6.0% is already below recommended targets and requires deintensification, not additional therapy. The American College of Physicians explicitly recommends deintensifying pharmacologic therapy when HbA1c falls below 6.5%, as no trials demonstrate clinical benefit at this level and the ACCORD trial showed increased mortality when targeting HbA1c <6.5% 1.
The KDIGO guidelines recommend an individualized HbA1c target ranging from 6.5% to 8.0% in patients with CKD not on dialysis, with this patient already at the lower end of acceptable control 1.
Targeting HbA1c below 7.0% in patients at risk of hypoglycemia (which includes those with CKD stage 3b) is explicitly not recommended 1.
Renal Function Limitations for Glycemic Control
The FDA label for dapagliflozin states it is "not recommended for use to improve glycemic control in adults with type 2 diabetes mellitus with an eGFR less than 45 mL/min/1.73 m²" as it is "likely to be ineffective in this setting based upon its mechanism of action" 2.
With eGFR 38 mL/min/1.73 m² (CKD stage 3b), the glucose-lowering efficacy of dapagliflozin is significantly attenuated, with placebo-adjusted HbA1c reduction of only 0.3% compared to 0.6% in patients with better renal function 3.
Alternative Indication: Renoprotection
When Dapagliflozin May Still Be Appropriate
Despite the above limitations for glycemic control, dapagliflozin 10 mg may be initiated if this patient has:
Confirmed type 2 diabetes (even with well-controlled HbA1c) AND albuminuria (UACR ≥30 mg/g) to reduce risk of eGFR decline, ESKD, cardiovascular death, and hospitalization for heart failure 4, 2.
The FDA label permits initiation at eGFR ≥25 mL/min/1.73 m² for non-glycemic indications (CKD progression, heart failure) 2.
The renoprotective and cardiovascular benefits of dapagliflozin persist regardless of baseline eGFR, with effects on blood pressure, body weight, and albuminuria reduction maintained even at lower eGFR levels 3.
Dosing for Renoprotection
Use dapagliflozin 10 mg once daily (not the 5 mg dose used for glycemic control) for CKD progression risk reduction 2.
The non-glucosuric benefits (blood pressure reduction, weight loss, albuminuria reduction) remain intact at eGFR 38 mL/min/1.73 m² 3.
Critical Clinical Pitfalls
Do Not Use If:
The patient does not have confirmed diabetes - the HbA1c of 6.0% alone does not confirm diabetes and may represent prediabetes or normal glycemia 1.
The patient lacks albuminuria or other cardiovascular indications - without these, there is no evidence-based indication for SGLT2 inhibitor therapy at this HbA1c level.
Volume depletion is present - correct volume status before initiating dapagliflozin 2.
Monitoring Requirements If Initiated
Check serum creatinine and potassium 1-2 weeks after initiation, as transient eGFR decline may occur 4.
Continue therapy even if eGFR falls below 25 mL/min/1.73 m² once started, as renoprotective benefits persist 2.
Do not rely solely on HbA1c for glycemic assessment at this level of renal function; supplement with self-monitoring of blood glucose or continuous glucose monitoring as HbA1c accuracy decreases below eGFR 30 mL/min/1.73 m² 1, 4.
What You Should Do Instead
For a patient with HbA1c 6.0% and eGFR 38:
Reduce or discontinue current glucose-lowering medications to avoid hypoglycemia risk, particularly if using insulin, sulfonylureas, or meglitinides 1.
Refer to nephrology immediately as all patients with CKD stage 3b require specialist co-management 4.
Optimize blood pressure control to <130/80 mmHg using RAS inhibitor therapy if albuminuria is present 4.
Only consider dapagliflozin 10 mg if the patient has confirmed diabetes with albuminuria (UACR ≥30 mg/g) for renoprotection, not glycemic control 4, 2.