What alternative medication can be started for a patient with type 2 diabetes, BGL of 11.8 mmol/L, HbA1c of 6.8%, on atypical antipsychotics, who declined metformin and sitagliptin, with a GFR of 72 mL/min?

Alternative Medication for Type 2 Diabetes in a 72-Year-Old Female on Atypical Antipsychotics

For a 72-year-old female with type 2 diabetes (BGL 11.8 mmol/L, HbA1c 6.8%) on atypical antipsychotics who has declined metformin and sitagliptin, a sodium-glucose cotransporter-2 (SGLT2) inhibitor is the most appropriate medication to start, given her adequate renal function (GFR 72 mL/min/1.73m²).

Medication Selection Algorithm

First-line considerations:

• SGLT2 inhibitors (preferred option):

  • Effective for glycemic control with HbA1c reductions of approximately 0.5-0.7% 1
  • Provide cardiovascular and renal protection 1
  • Low risk of hypoglycemia 1
  • Associated with weight loss rather than weight gain 2
  • Safe with GFR >30 mL/min/1.73m² 1

• GLP-1 receptor agonists (alternative option):

  • Effective glycemic control with low hypoglycemia risk 1
  • Weight loss benefit of 2-4 kg 1
  • Improved lipid profiles 1
  • Cardiovascular benefits in high-risk patients 1
  • Subcutaneous administration may be a limitation 1

Second-line considerations (if SGLT2 inhibitors and GLP-1 receptor agonists are declined):

• DPP-4 inhibitors (specifically linagliptin):
  • No dose adjustment needed with her GFR 1, 3
  • Weight neutral 4, 5
  • Low hypoglycemia risk 4, 5
  • Once-daily dosing 3

Specific SGLT2 Inhibitor Recommendations

For this patient with GFR of 72 mL/min/1.73m²:

• Dapagliflozin 10 mg daily is appropriate 1
• Canagliflozin 100 mg daily is appropriate 1
• Empagliflozin 10 mg daily is appropriate 1

Important Considerations and Monitoring

• Efficacy monitoring:

  • Check HbA1c after 3 months of therapy 1
  • Monitor fasting and postprandial glucose levels 1

• Safety monitoring:

  • Watch for genital mycotic infections (6% risk vs. 1% with placebo) 1
  • Monitor for symptoms of volume depletion, especially if on other diuretics 1
  • Be alert for euglycemic ketoacidosis, particularly during acute illness 1
  • Educate on daily hygiene measures to reduce infection risk 1

• Special considerations with atypical antipsychotics:

  • Avoid thiazolidinediones (TZDs) as they may increase risk of heart failure, which could be problematic with atypical antipsychotics that may have metabolic effects 1, 6
  • SGLT2 inhibitors' weight loss effect may help counteract weight gain often associated with atypical antipsychotics 2

Contraindications and Cautions

• Avoid thiazolidinediones (pioglitazone) due to:

  • Risk of fluid retention and heart failure 1, 6
  • Weight gain concerns, especially problematic with atypical antipsychotics 6
  • Potential increased cardiovascular risk 6

• Sulfonylureas should be used with caution due to:

  • Higher risk of hypoglycemia, especially in older adults 6
  • Associated weight gain 6
  • May have higher secondary failure rate compared to other agents 6

Patient Education Points

• Explain that SGLT2 inhibitors work by increasing glucose excretion through the kidneys 1
• Emphasize importance of adequate hydration 1
• Instruct on genital hygiene to prevent infections 1
• Advise to temporarily discontinue medication during acute illness or prior to surgical procedures 1
• Explain symptoms of ketoacidosis that require immediate medical attention 1

This approach prioritizes medications with proven cardiovascular benefits, low hypoglycemia risk, and favorable effects on weight, which are particularly important considerations in an elderly patient on atypical antipsychotics.