Can Toujeo (insulin glargine) and Lantus (insulin glargine) be switched 1:1?

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Last updated: March 3, 2025View editorial policy

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From the Guidelines

Toujeo and Lantus cannot be switched on a simple 1:1 basis due to differences in their formulations and pharmacokinetic profiles. When considering the switch between these two insulin glargine products, it's crucial to understand the distinction in their concentrations, with Toujeo being a more concentrated formulation (300 units/mL) compared to Lantus (100 units/mL) 1. This difference affects their release patterns, with Toujeo providing a more gradual and extended release. As a result, patients transitioning from Lantus to Toujeo may require a higher dose of Toujeo, approximately 10-20% more, to maintain the same level of glycemic control. Conversely, switching from Toujeo to Lantus may necessitate reducing the Lantus dose by about 10-20% from the previous Toujeo dose. Key factors to consider during this transition include:

  • The need for medical supervision
  • Careful blood glucose monitoring for several days after the switch
  • Potential dose adjustments based on individual patient response
  • Awareness of changes in insulin needs during the transition period
  • Consideration of meal timing, exercise patterns, and concurrent medications, which can influence the response to the switch between these insulin formulations. Given the information from the standards of medical care in diabetes-2021, it's clear that the choice and adjustment of basal insulin, such as Toujeo and Lantus, should be tailored to the individual patient's needs and monitored closely to achieve optimal glycemic control while minimizing the risk of hypoglycemia 1.

From the Research

Insulin Glargine Formulations

  • Toujeo (insulin glargine 300 U/mL) and Lantus (insulin glargine 100 U/mL) are two different formulations of insulin glargine 2, 3
  • They have different pharmacokinetic and pharmacodynamic profiles, with Toujeo having a flatter and longer profile 2

Dose Adjustment

  • The two insulin formulations are not bioequivalent, and a dose adjustment may be required when switching from one to the other 2, 4
  • Studies have shown that patients may require a slightly higher daily insulin dose with Toujeo compared to Lantus 2, 3, 4
  • A 1:1 dose interchange between Toujeo and Lantus may not be suitable, and a dose reduction may be necessary when transitioning from Toujeo to another insulin formulation, such as insulin detemir 5

Efficacy and Safety

  • Both Toujeo and Lantus have been shown to be effective in achieving glycemic control, with Toujeo having a lower risk of hypoglycemia, especially at night 2, 3, 4, 6
  • Toujeo has also been associated with a slightly smaller weight gain compared to Lantus 2, 4
  • The safety profile of Toujeo is similar to that of Lantus, with a low risk of hypoglycemic events 2, 3, 4, 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

[INSULIN GLARGINE 300 U/mL (TOUJEO®)].

Revue medicale de Liege, 2016

Research

The role of Toujeo®, insulin glargine U-300, in the treatment of diabetes mellitus.

Journal of the American Association of Nurse Practitioners, 2016

Research

Real-World Effectiveness of Insulin Glargine 300 Initiation in Switzerland.

Diabetes, metabolic syndrome and obesity : targets and therapy, 2020

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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