At what blood glucose level should glargine (insulin glargine) be held?

Holding Glargine Insulin Based on Blood Glucose Levels

Glargine insulin should be held when blood glucose levels fall below 70 mg/dL (3.9 mmol/L) to prevent hypoglycemia. 1

Understanding Glargine Insulin and Hypoglycemia Risk

Glargine (Lantus) is a long-acting basal insulin that:

• Releases insulin slowly over 24 hours with no peak action time
• Provides more physiologic basal insulin levels
• Has a more consistent absorption pattern than intermediate-acting insulins
• Reduces the risk of hypoglycemia compared to other long-acting insulins 1

Blood Glucose Thresholds for Insulin Management

When to Hold Glargine:

• Blood glucose <70 mg/dL (3.9 mmol/L): This is the standard definition of hypoglycemia and the threshold at which glargine should be held 1
• If blood glucose falls below this level, the insulin regimen should be reassessed and modified

Warning Signs and Monitoring:

• When blood glucose falls below 100 mg/dL (5.6 mmol/L), consider:
  • Providing a small snack to prevent further decline 1
  • Reassessing the insulin regimen to avoid potential hypoglycemia 1

Hypoglycemia Management Protocol

If hypoglycemia occurs (<70 mg/dL or 3.9 mmol/L):

1. Administer 15-20g of glucose for conscious patients
2. Recheck blood glucose after 15 minutes
3. If hypoglycemia persists, repeat treatment
4. Once blood glucose normalizes, provide a meal or snack to prevent recurrence 1

Special Considerations for Hospitalized Patients

For hospitalized patients on glargine:

• Critical care patients: Target blood glucose 140-180 mg/dL (7.8-10.0 mmol/L) 1
• Non-critical patients: Target pre-meal glucose <140 mg/dL (7.8 mmol/L) and random glucose <180 mg/dL (10.0 mmol/L) 1
• Severe hypoglycemia in hospitalized patients is defined as <40 mg/dL (2.2 mmol/L) 1

Important Clinical Pitfalls to Avoid

1. Don't rely solely on sliding scale insulin (SSI): Basal insulin like glargine should be part of a comprehensive regimen, not replaced by SSI alone 1

2. Be cautious with inaccurate readings: Faulty meters or improper testing techniques can provide misleading blood glucose values, leading to inappropriate insulin dosing decisions 1

3. Monitor for hypoglycemia unawareness: Patients with recurrent hypoglycemia may develop impaired awareness of low blood glucose, requiring more vigilant monitoring and higher glycemic targets 1

4. Consider individual factors: Adjust thresholds based on:

   • History of severe hypoglycemia
   • Hypoglycemia unawareness
   • Duration of diabetes
   • Life expectancy and comorbidities 1

By following these guidelines, clinicians can safely administer glargine insulin while minimizing the risk of dangerous hypoglycemic episodes.