What are the indications and mechanism of action of Farxiga (dapagliflozin)?

Farxiga (Dapagliflozin): Indications and Mechanism of Action

Mechanism of Action

Farxiga works by selectively inhibiting sodium-glucose cotransporter-2 (SGLT2) proteins in the proximal tubule of the kidney, blocking up to 90% of filtered glucose reabsorption and promoting urinary glucose excretion. 1, 2 This insulin-independent mechanism reduces blood glucose by forcing the kidneys to excrete excess glucose rather than reabsorb it back into the bloodstream 3, 4. The SGLT2 proteins are upregulated in chronic hyperglycemia, increasing glucose reabsorption capacity—dapagliflozin directly counteracts this pathological adaptation 1.

Beyond glucose lowering, the glucosuria induced by dapagliflozin triggers secondary beneficial effects including modest natriuresis, reduced intraglomerular pressure through tubuloglomerular feedback, and decreased cardiac preload 1, 5. These pleiotropic effects explain why dapagliflozin benefits extend far beyond glycemic control to cardiovascular and renal protection.

FDA-Approved Indications

The FDA has approved dapagliflozin 10 mg once daily for four distinct indications 2:

1. Chronic Kidney Disease (CKD) at Risk of Progression

• To reduce the risk of sustained eGFR decline, end-stage kidney disease (ESKD), cardiovascular death, and hospitalization for heart failure in adults with CKD at risk of progression 2
• This indication is supported by the DAPA-CKD trial showing 44% reduction in the composite renal outcome 6
• Not recommended for polycystic kidney disease or patients requiring/with recent immunosuppressive therapy for kidney disease 2

2. Heart Failure (Any Ejection Fraction)

• To reduce the risk of cardiovascular death, hospitalization for heart failure, and urgent heart failure visits in adults with heart failure 2
• The DAPA-HF trial demonstrated 26% reduction in worsening heart failure or CV death in HFrEF patients, with consistent benefits regardless of diabetes status 6, 7
• EMPEROR-Reduced showed concordant 25% risk reduction 6, 8
• Benefits extend to HFpEF based on recent evidence 9, 10

3. Type 2 Diabetes with Cardiovascular Risk

• To reduce the risk of hospitalization for heart failure in adults with type 2 diabetes and either established cardiovascular disease OR multiple cardiovascular risk factors 7, 2
• DECLARE-TIMI 58 showed 27% reduction in hospitalization for heart failure 11, 9

4. Glycemic Control in Type 2 Diabetes

• As adjunct to diet and exercise to improve glycemic control in adults and pediatric patients aged 10 years and older with type 2 diabetes mellitus 2
• Starting dose: 5 mg once daily, can increase to 10 mg for additional glycemic benefit 7
• Achieves HbA1c reduction of 0.5-0.7% with 10 mg dose 1

Critical Dosing and Renal Function Considerations

For glycemic control in type 2 diabetes:

• eGFR ≥45 mL/min/1.73 m²: Use as indicated
• eGFR <45 mL/min/1.73 m²: NOT recommended for glycemic control (ineffective due to mechanism of action) 7, 2

For heart failure and CKD indications:

• Can be used down to eGFR ≥25 mL/min/1.73 m² 6, 12
• eGFR <30 mL/min/1.73 m²: Contraindicated 7
• ESKD or dialysis: Contraindicated 7

Key Safety Considerations

Common pitfalls to avoid:

• Discontinue at least 3 days before planned surgery to prevent postoperative ketoacidosis 7
• Assess volume status before initiation; correct volume depletion first 2
• Monitor for genital mycotic infections (more common in women) and urinary tract infections 7, 3
• Risk of euglycemic diabetic ketoacidosis, especially with insulin dose reduction, prolonged fasting, or carbohydrate restriction 11, 9
• When combining with sulfonylureas or insulin, reduce those doses by ~20% to prevent hypoglycemia 7
• Absolute contraindications: pregnancy, breastfeeding, serious hypersensitivity reaction to drug 7

Clinical Integration Algorithm

For patients with type 2 diabetes:

1. If HFrEF present → Start dapagliflozin 10 mg regardless of glycemic control 6, 10
2. If CKD with albuminuria (eGFR 25-75) → Start dapagliflozin 10 mg 6, 12
3. If established CVD or multiple CV risk factors → Start dapagliflozin 10 mg to prevent heart failure 7
4. For glycemic control alone (eGFR ≥45) → Start 5 mg, titrate to 10 mg as needed 2

For patients without diabetes:

• HFrEF (any NYHA class II-IV, EF ≤40%) → Dapagliflozin 10 mg as foundational therapy 6, 13, 8
• CKD with proteinuria (eGFR 25-75, UACR 22.6-565.6 mg/mmol) → Dapagliflozin 10 mg 6

The cardiovascular and renal benefits of dapagliflozin occur independent of glucose-lowering effects and are consistent across diabetes status 6, 13, 8.