Can you take Farxiga (dapagliflozin) and Xigduo (dapagliflozin and metformin) together?

Taking Farxiga and Xigduo Together is Not Recommended

Taking both Farxiga (dapagliflozin) and Xigduo (dapagliflozin and metformin) together is not recommended as this would result in duplicate dosing of dapagliflozin, which could increase the risk of adverse effects without additional therapeutic benefit.

Understanding the Medications

Farxiga and Xigduo contain overlapping active ingredients:

• Farxiga: Contains dapagliflozin, an SGLT2 inhibitor
• Xigduo: Contains both dapagliflozin and metformin extended release in a fixed-dose combination

Rationale Against Combined Use

1. Duplicate Medication: Taking both medications would provide a double dose of dapagliflozin, which:

   • Is not supported by clinical guidelines
   • May increase the risk of side effects without additional glycemic benefit
   • Could potentially lead to dose-dependent adverse effects

2. Safety Concerns: Doubling the dose of dapagliflozin could increase the risk of:

   • Genital mycotic infections (already occurs in about 6% of SGLT2 inhibitor users compared to 1% with placebo) 1
   • Urinary tract infections
   • Volume depletion and hypotension
   • Euglycemic diabetic ketoacidosis (a rare but serious side effect)

Appropriate Medication Options

For Patients Already on Metformin:

• If you need additional glycemic control, adding Farxiga (dapagliflozin) to metformin is appropriate 1
• Alternatively, switching from separate medications to the fixed-dose combination Xigduo (dapagliflozin + metformin) can improve adherence 2

For Patients Not on Either Medication:

• Metformin remains the first-line therapy for type 2 diabetes 1
• For patients requiring combination therapy, Xigduo provides the benefit of both medications in a single tablet 2, 3
• Clinical trials have shown that the combination of dapagliflozin and metformin can reduce HbA1c by up to 2%, with additional benefits of weight loss (2-3 kg) and modest blood pressure reduction (3-5 mmHg) 2

Dosing Considerations

• Dapagliflozin dosing is typically 10 mg once daily for glycemic control 1
• In patients with renal impairment:
  • For eGFR 30-44 mL/min/1.73 m²: Dapagliflozin 10 mg daily is appropriate
  • For eGFR <25 mL/min/1.73 m²: Initiation is not recommended
  • For eGFR <20 mL/min/1.73 m²: Initiation is not recommended, but may continue if tolerated for kidney and cardiovascular benefit until dialysis 1

Monitoring Recommendations

When using either Farxiga or Xigduo:

1. Volume Status: Monitor for signs of hypovolemia, especially during initiation
2. Glycemic Control: Regular blood glucose monitoring and HbA1c assessment
3. Renal Function: Monitor eGFR, particularly in the first few weeks of therapy
4. Ketone Monitoring: Consider blood or urine ketone monitoring in high-risk patients (e.g., those on insulin)
5. Infection Signs: Watch for symptoms of genital mycotic infections or urinary tract infections

Important Precautions

• Pause SGLT2 inhibitor treatment during periods of acute illness or stressors to reduce the risk of euglycemic ketoacidosis 1
• Maintain at least low-dose insulin in patients requiring insulin therapy to minimize the risk of ketoacidosis 1
• Implement daily hygienic measures to reduce the risk of genital mycotic infections 1

In conclusion, the appropriate approach is to use either Farxiga or Xigduo, but not both simultaneously, as part of your diabetes management plan.