Direct Dose Conversion: Basaglar to Lantus
The dose remains 20 units daily when switching from Basaglar to Lantus, as both are insulin glargine formulations with equivalent potency requiring a 1:1 dose conversion. 1
Why the Dose Stays the Same
Both Basaglar and Lantus contain insulin glargine 100 units/mL and are bioequivalent formulations with identical pharmacokinetic profiles 2, 3. The American Diabetes Association guidelines for insulin glargine dosing make no distinction between different insulin glargine products when converting between them 1.
- Unit-for-unit conversion is standard: When switching between insulin glargine products (Lantus, Basaglar, or other biosimilars), maintain the same total daily dose 1, 4
- No dose adjustment needed: Clinical studies demonstrate that switching between insulin glargine formulations at equivalent doses maintains glycemic control without requiring dose changes 4
- Timing remains unchanged: Continue once-daily administration at the same time of day as the previous regimen 1, 3
Monitoring After the Switch
- Check fasting blood glucose daily for the first week after switching to identify any unexpected changes in glycemic control 1
- Target fasting glucose of 80-130 mg/dL should be maintained with the equivalent dose 1
- Adjust only if needed: If fasting glucose is 140-179 mg/dL, increase by 2 units every 3 days; if ≥180 mg/dL, increase by 4 units every 3 days 1
- Reduce by 10-20% if hypoglycemia occurs without clear cause 1
Common Pitfall to Avoid
Do not reduce the dose preemptively when switching between insulin glargine products, as this will result in inadequate basal coverage and hyperglycemia 1. The biosimilar-to-originator switch has been shown to maintain or improve glycemic control at equivalent doses 4.