Lantus Dosing Conversion from Levemir
Convert Levemir to Lantus using a unit-for-unit conversion initially, then reduce the total daily dose by 10-20% if the patient is at high risk for hypoglycemia or was on twice-daily Levemir dosing. 1
Standard Conversion Approach
For most patients, convert the total daily dose of Levemir to Lantus on a 1:1 unit basis and administer once daily. 1 This straightforward approach works well for patients who are not in very tight glycemic control and have low hypoglycemia risk.
When to Reduce the Initial Dose
- Reduce the converted dose by 10-20% for patients at high risk of hypoglycemia (elderly, renal impairment, history of severe hypoglycemia, or those in very tight glycemic management). 1
- Reduce by 10-20% when converting from twice-daily Levemir to once-daily Lantus, as Levemir typically requires higher total daily doses to achieve equivalent glycemic control. 1, 2
Key Dosing Differences Between Levemir and Lantus
The evidence consistently shows that Levemir requires approximately 1.8 times the dose of Lantus to achieve similar glycemic control when both are optimally titrated. 2, 3 In head-to-head trials:
- Mean Levemir dose: 0.78 units/kg/day (with 55% of patients requiring twice-daily dosing) 3
- Mean Lantus dose: 0.44 units/kg/day (once-daily dosing) 3
This dose difference is particularly pronounced in patients who were on twice-daily Levemir (1.00 units/kg/day for twice-daily Levemir vs 0.52 units/kg/day for once-daily Levemir). 3
Practical Conversion Algorithm
- Calculate total daily Levemir dose (if twice-daily, add both doses together). 1
- For standard-risk patients: Convert unit-for-unit to once-daily Lantus. 1
- For high-risk patients or those on twice-daily Levemir: Reduce by 10-20% from the total daily Levemir dose. 1
- Titrate based on fasting glucose monitoring: Increase by 2-4 units every 3 days until fasting glucose reaches 80-130 mg/dL. 1, 4
Post-Conversion Monitoring
- Monitor fasting blood glucose daily during the first 1-2 weeks after conversion to assess adequacy of the new dose. 1, 4
- Adjust dose every 3 days based on fasting glucose values: increase by 2 units if fasting glucose is 140-179 mg/dL, or by 4 units if ≥180 mg/dL. 4
- If hypoglycemia occurs, reduce dose immediately by 10-20% and reassess the conversion. 1, 4
Critical Pitfalls to Avoid
- Do not assume equal potency: Levemir and Lantus are not equipotent on a unit-per-unit basis when optimally dosed, though initial conversion can start 1:1 with subsequent titration. 2, 3
- Do not continue twice-daily dosing with Lantus: Unlike Levemir, Lantus is designed for once-daily administration and should not routinely be split into twice-daily dosing during conversion. 1
- Watch for overbasalization: If the converted Lantus dose exceeds 0.5 units/kg/day and glycemic control remains suboptimal, consider adding prandial insulin rather than continuing to escalate basal insulin. 1, 4