How much should the Lantus (insulin glargine) dose be increased for a patient with fasting hyperglycemia and a current dose of 16 units?

Adjusting Lantus Dose for Elevated Fasting Blood Glucose

For a fasting blood glucose of 192 mg/dL with current Lantus dose of 16 units, increase the Lantus dose by 2-4 units (to 18-20 units) and continue to monitor fasting glucose levels.

Rationale for Dose Adjustment

• A fasting blood glucose of 192 mg/dL indicates inadequate glycemic control, as it significantly exceeds the typical target range of <130 mg/dL for fasting glucose 1
• The current basal insulin dose of 16 units is not providing adequate overnight glucose control, requiring an upward adjustment 2, 1
• An increase of 2-4 units (approximately 10-25% of current dose) is a standard adjustment for persistent hyperglycemia 1, 3

Recommended Titration Protocol

• Increase Lantus dose to 18-20 units and administer at the same time each day 3
• Continue to monitor fasting blood glucose daily 2
• If fasting glucose remains >130 mg/dL for 3 consecutive days after this adjustment, increase by another 2 units 1
• If any hypoglycemia occurs (glucose <70 mg/dL), reduce dose by 2-4 units 1

Ongoing Dose Adjustment Algorithm

• Follow this simple algorithm for continued titration 2, 1:
  • If 50% of fasting glucose readings over a week are above target: Increase dose by 2 units
  • If any fasting glucose reading is <80 mg/dL: Decrease dose by 2 units
  • If fasting glucose is between 110-130 mg/dL: Maintain current dose

Important Considerations

• Daily self-monitoring of blood glucose is essential during this dose adjustment phase 2
• Avoid excessive dose increases (>10% at once) as this increases hypoglycemia risk 1
• The timing of Lantus administration should be consistent each day, though it can be given at any time of day 3, 4
• Dosage adjustments should only be made under medical supervision with appropriate glucose monitoring 3

Special Situations and Precautions

• If fasting glucose normalizes but overall glycemic control remains poor (elevated HbA1c), consider whether prandial insulin coverage might be needed 2
• Be aware that once the daily basal insulin dose exceeds 0.5 units/kg/day, the addition of prandial insulin may be more appropriate than further basal insulin increases 2
• Insulin glargine (Lantus) has a lower risk of nocturnal hypoglycemia compared to NPH insulin, which is beneficial when titrating doses 5
• For patients with significant insulin resistance, higher doses may be needed, but should be approached cautiously with incremental adjustments 1