How to switch from Lantus (insulin glargine) twice daily (bid) to once daily (qd)?

Switching from Lantus (Insulin Glargine) Twice Daily to Once Daily

When switching from twice-daily Lantus (insulin glargine) to once-daily dosing, combine the total daily dose and administer 80% of this amount as a single daily dose, preferably at bedtime. 1

Rationale for Dose Adjustment

When transitioning from a twice-daily basal insulin regimen to once-daily dosing, a dose reduction is recommended to lower the risk of hypoglycemia:

• The 80% conversion factor is specifically recommended in clinical guidelines when consolidating multiple daily doses of insulin into a single dose 1
• This reduction accounts for differences in pharmacokinetics when administering the full daily dose at one time

Step-by-Step Conversion Process

1. Calculate total daily dose: Add both current Lantus doses together
2. Apply conversion factor: Multiply the total by 0.80 (80%)
3. Choose administration time: Administer preferably at bedtime, though morning administration is also acceptable 2
4. Monitor closely: Check blood glucose more frequently during the transition period 3

Example Calculation

For a patient currently on Lantus 20 units in the morning and 15 units at night:

• Total daily dose: 35 units
• New once-daily dose: 35 × 0.80 = 28 units

Timing Considerations

While traditionally administered at bedtime, insulin glargine can be given at any time of day as long as it's consistent:

• The FDA label for Lantus states it can be administered "at any time of day but at the same time every day" 3
• Studies show equivalent glycemic control and nocturnal hypoglycemia rates whether administered in the morning or at bedtime 2

Post-Transition Monitoring and Adjustment

• Increase blood glucose monitoring frequency during the transition period 3
• Set a fasting plasma glucose (FPG) target
• Adjust dose using an evidence-based titration algorithm:
  • Increase by 2 units every 3 days until reaching FPG goal without hypoglycemia
  • For hypoglycemia without clear cause, reduce dose by 10-20% 1

Potential Pitfalls and Caveats

• Hypoglycemia risk: Monitor closely during the first few days after transition
• Rebound hyperglycemia: If the single dose is insufficient, blood glucose may rise before the next dose
• Individual variation: Some patients may require closer to 90% of their previous total daily dose based on individual insulin sensitivity
• Consistency is key: Administer at the same time each day to maintain stable insulin levels 3

Remember that insulin glargine should not be mixed with other insulins in the same syringe due to its acidic pH 4, 5.