Converting from Toujeo 36 Units to Lantus: Dose Equivalence
When converting a patient from Toujeo 36 units subcutaneous daily to Lantus, the equivalent dose should be 36 units of Lantus subcutaneous daily (1:1 conversion).
Rationale for Dose Conversion
Toujeo (insulin glargine U-300) and Lantus (insulin glargine U-100) are both long-acting basal insulin analogs containing the same active ingredient (insulin glargine), but at different concentrations:
- Toujeo contains 300 units/mL (U-300)
- Lantus contains 100 units/mL (U-100)
Despite the concentration difference, clinical guidelines support a 1:1 unit conversion when switching between these insulins:
- The same number of units should be prescribed when converting between Toujeo and Lantus 1
- The total daily insulin dose remains the same, with the only change being the insulin formulation 1
Implementation Considerations
When converting from Toujeo to Lantus, consider these important factors:
- Timing of administration: Lantus should be administered at the same time of day as the patient was taking Toujeo
- Blood glucose monitoring: More frequent monitoring is recommended for 3-7 days after conversion
- Dose adjustments: May be needed after transition based on blood glucose patterns
- Patient education: Explain that while the number of units remains the same, the volume of insulin will be different due to the concentration change
Potential Clinical Differences
Despite the 1:1 unit conversion, be aware of potential differences in clinical effect:
- Lantus may have a slightly different pharmacokinetic profile compared to Toujeo
- Toujeo typically has a more prolonged and stable glucose-lowering effect with less day-to-day variability 2
- Patients may experience slightly different glycemic control or hypoglycemia risk after conversion
Monitoring and Follow-up
After converting to Lantus 36 units daily:
- Monitor fasting blood glucose levels daily for the first week
- Adjust Lantus dose as needed based on fasting glucose patterns:
- FBG ≥180 mg/dL: Increase by 6-8 units
- FBG 140-179 mg/dL: Increase by 4 units
- FBG 120-139 mg/dL: Increase by 2 units
- FBG <100 mg/dL: Decrease by 2-4 units
- Any hypoglycemia (<70 mg/dL): Decrease by 10-20% 3
Special Considerations
- For patients with renal impairment: Consider a slightly reduced starting dose due to decreased insulin clearance 3
- For patients on glucocorticoids: May require higher insulin doses to manage steroid-induced hyperglycemia
- For patients with history of hypoglycemia: Monitor more closely after conversion
Remember that while the unit conversion is 1:1, individual patient response may vary, necessitating close monitoring and potential dose adjustments after the transition.