What are the considerations before starting Sodium-Glucose Linked Transporter 2 (SGLT2) inhibitors?

Key Considerations Before Starting SGLT2 Inhibitors

Before initiating SGLT2 inhibitors, clinicians should assess renal function, volume status, risk of ketoacidosis, and potential for drug interactions, as these medications provide significant cardiovascular and renal benefits but require careful patient selection and monitoring. 1

Patient Selection and Eligibility Assessment

Renal Function

• eGFR assessment is mandatory before initiation:
  • SGLT2 inhibitors are recommended for patients with T2DM and CKD with eGFR ≥20 ml/min/1.73 m² 1
  • For glycemic control purposes, SGLT2 inhibitors may be less effective when eGFR <45 ml/min/1.73 m² 1
  • Once initiated, SGLT2 inhibitors can be continued even if eGFR falls below 20 ml/min/1.73 m² unless not tolerated or kidney replacement therapy is initiated 1

Cardiovascular and Renal Risk Assessment

• Prioritize SGLT2 inhibitors for patients with:
  • Established cardiovascular disease
  • Heart failure (particularly with reduced ejection fraction)
  • Chronic kidney disease
  • Multiple cardiovascular risk factors 1

Medication Review

• Evaluate current antihyperglycemic regimen:
  • If patient is on insulin or sulfonylureas and meeting glycemic targets, consider reducing doses of these medications by approximately 20% to prevent hypoglycemia 1
  • If patient is on diuretics and at risk for hypovolemia, consider decreasing thiazide or loop diuretic dosages before starting SGLT2i 1

Risk Assessment for Potential Adverse Effects

Volume Depletion Risk

• Assess for:
  • History of hypotension
  • Tenuous volume status
  • Concurrent diuretic use
  • History of acute kidney injury
  • Elderly patients 1, 2

Ketoacidosis Risk

• Identify risk factors:
  • Insulin deficiency
  • Reduced caloric intake
  • History of alcohol abuse
  • Pancreatic disorders
  • Planned surgery or procedures requiring fasting 2

Infection Risk

• Evaluate risk for:
  • Recurrent urinary tract infections
  • History of genital mycotic infections
  • Immunosuppression (particularly in transplant recipients) 1, 2

Pre-Initiation Counseling and Education

Patient Education on Potential Adverse Effects

• Genital mycotic infections and importance of genital hygiene
• Symptoms of volume depletion (lightheadedness, orthostasis, weakness)
• Signs and symptoms of diabetic ketoacidosis (nausea, vomiting, abdominal pain, malaise)
• Foot care, especially in patients with neuropathy 1, 2

Sick Day Management

• Instruct patients to:
  • Withhold SGLT2i during times of prolonged fasting, surgery, or critical illness
  • Monitor blood glucose more frequently during illness
  • Maintain adequate hydration
  • Seek medical attention if unable to maintain hydration or if experiencing symptoms of ketoacidosis 1, 2

Perioperative Considerations

Surgery and Procedures

• Withhold SGLT2i for at least 3 days before major surgery or procedures requiring prolonged fasting
• Resume only when the patient is clinically stable and has resumed normal oral intake 1, 2

Monitoring After Initiation

Short-term Monitoring

• Expect a reversible decrease in eGFR (3-5 ml/min/1.73 m²) after initiation, which is generally not an indication to discontinue therapy 1
• Monitor for signs of volume depletion and hypotension, particularly in the first few weeks
• More frequent blood glucose monitoring in patients on insulin or sulfonylureas 1

Long-term Monitoring

• Regular assessment of renal function
• Ongoing surveillance for urinary tract infections and genital mycotic infections
• Periodic foot examinations 2

Special Populations

Kidney Transplant Recipients

• SGLT2i have not been adequately studied in kidney transplant recipients
• Use with caution due to immunosuppression and potentially increased risk for infections 1

Heart Failure Patients

• SGLT2i have demonstrated significant benefits in heart failure patients
• Can be initiated in hospitalized patients with heart failure with reduced ejection fraction 1

Practical Algorithm for SGLT2i Initiation

1. Assess eligibility: Confirm eGFR ≥20 ml/min/1.73 m²
2. Evaluate cardiovascular and renal risk: Higher benefit in those with established disease
3. Review current medications: Adjust insulin, sulfonylureas, or diuretics if needed
4. Assess risk factors for adverse effects: Volume status, ketoacidosis risk, infection risk
5. Provide patient education: Sick day management, signs of adverse effects
6. Initiate monitoring plan: Renal function, volume status, glycemic control
7. Schedule appropriate follow-up: Assess for initial eGFR dip and medication tolerance

By carefully considering these factors before initiating SGLT2 inhibitors, clinicians can maximize benefits while minimizing risks in patients with type 2 diabetes.