What is the starting dose of Xigduo (dapagliflozin and metformin)?

Starting Dose of Xigduo (Dapagliflozin and Metformin)

The recommended starting dose of Xigduo is dapagliflozin 5 mg plus metformin 500 mg once daily, with gradual titration to minimize gastrointestinal side effects.

Dosing Considerations

Initial Dosing

• Start with dapagliflozin 5 mg plus metformin 500 mg once daily
• Titrate upward gradually over 1-2 weeks based on efficacy and tolerability
• Target dose is typically dapagliflozin 10 mg plus metformin 2000 mg daily (often divided into twice-daily dosing)

Renal Function Adjustments

• eGFR ≥45 mL/min/1.73 m²: Standard dosing applies
• eGFR 30-44 mL/min/1.73 m²: Reduce metformin to maximum 1000 mg/day; dapagliflozin can remain at 10 mg daily 1
• eGFR <30 mL/min/1.73 m²: Xigduo is contraindicated due to metformin component 1

Titration Protocol

1. Week 1: Dapagliflozin 5 mg + Metformin 500 mg once daily
2. Week 2: If tolerated, increase to dapagliflozin 5 mg + metformin 500 mg twice daily
3. Week 3-4: If needed and tolerated, increase to dapagliflozin 10 mg + metformin 1000 mg twice daily

Special Populations

Elderly Patients

• Consider starting at the lower end of the dosing range
• Monitor renal function more frequently (every 3-6 months)
• Be vigilant for volume depletion signs 1

Patients with Renal Impairment

• Monitor eGFR before initiation and at least annually
• Increase monitoring frequency when eGFR <60 mL/min/1.73 m² (every 3-6 months) 1
• Dapagliflozin's glucose-lowering effect diminishes at eGFR <45 mL/min/1.73 m², but cardiovascular and renal benefits persist 1

Important Monitoring and Precautions

Fluid Management

• Advise patients to maintain adequate hydration (2-3 liters daily) 2
• Monitor for signs of volume depletion (dizziness, lightheadedness, orthostatic hypotension)
• Consider reducing dose of concurrent diuretics when initiating Xigduo 2

Infection Risk

• Counsel patients about increased risk of genital mycotic infections (occurs in ~6% of patients on SGLT2 inhibitors vs. 1% on placebo) 1, 2
• Advise on proper genital hygiene to reduce infection risk 2

Metabolic Monitoring

• Monitor for signs of ketoacidosis, particularly during illness or fasting periods
• Temporarily discontinue during severe illness or before surgical procedures 2
• Monitor vitamin B12 levels if on metformin for >4 years 1

Efficacy Expectations

Clinical trials have shown that combination therapy with dapagliflozin plus metformin provides superior glycemic control compared to either agent alone:

• HbA1c reduction of approximately 2% with combination therapy vs. 1.2-1.4% with monotherapy 3
• Additional benefits include weight reduction and blood pressure lowering 4

Common Pitfalls to Avoid

1. Failing to assess renal function before initiation
2. Not educating patients about genital infection risk and prevention
3. Overlooking the need for adequate hydration
4. Neglecting to adjust concurrent diuretic therapy
5. Missing the opportunity to continue dapagliflozin for cardiorenal benefits even when eGFR declines below 45 mL/min/1.73 m² 1

Remember that while glucose-lowering efficacy of dapagliflozin decreases with declining renal function, the cardiovascular and kidney benefits are preserved, making it valuable beyond glycemic control in appropriate patients 1, 2.