If a patient is being switched from insulin glargine (Insulin Glargine) 100U/ml to Toujeo (Insulin Glargine) 300U/ml, what dose of Toujeo would be equivalent to 30 units of insulin glargine 100U/ml?

Converting Insulin Glargine 100 U/ml to Toujeo 300 U/ml

When switching from insulin glargine 100 U/ml at a dose of 30 units to Toujeo 300 U/ml, the patient should receive 24 units of Toujeo (which is 80% of the original dose).

Dosing Conversion Guidelines

The FDA-approved drug label for insulin glargine provides specific guidance for switching between insulin concentrations 1:

• When switching from once-daily Toujeo (insulin glargine 300 U/ml) to once-daily insulin glargine 100 U/ml, the recommended starting dose is 80% of the Toujeo dosage
• Therefore, when converting in the opposite direction (from insulin glargine 100 U/ml to Toujeo 300 U/ml), the same 80% conversion factor should be applied

Calculation

• Current dose: 30 units of insulin glargine 100 U/ml
• Conversion factor: 80%
• Toujeo dose: 30 units × 0.8 = 24 units

Pharmacological Considerations

Toujeo (insulin glargine 300 U/ml) has distinct pharmacokinetic properties compared to standard insulin glargine 100 U/ml:

• U-300 glargine has a longer duration of action than U-100 glargine but modestly lower efficacy per unit administered 2
• The two insulin formulations are not bioequivalent, and the daily insulin requirement is typically higher with insulin glargine 300 U/ml 3
• Clinical trials have shown that patients receiving Toujeo required approximately 10-12% more insulin to achieve the same glycemic control as those on insulin glargine 100 U/ml 4

Clinical Implications

When switching to Toujeo 300 U/ml, healthcare providers should be aware of:

• The need for close monitoring of blood glucose levels during the transition period 1
• Potential benefits of Toujeo including:
  • Lower risk of nocturnal hypoglycemia 5
  • More stable and prolonged pharmacokinetic profile 5
  • Greater flexibility in injection timing 3

Common Pitfalls to Avoid

1. Dosing errors: Never use standard U-100 insulin syringes to administer Toujeo, as this could lead to severe dosing errors. Toujeo is only available in prefilled pens to minimize this risk 2.

2. Failure to adjust dose: Some patients may require dose adjustments after the initial conversion. Monitor blood glucose closely during the transition period 1.

3. Assuming bioequivalence: Remember that insulin glargine 100 U/ml and Toujeo 300 U/ml are not bioequivalent on a unit-per-unit basis 3.

By following the recommended 80% conversion factor when switching from insulin glargine 100 U/ml to Toujeo 300 U/ml, healthcare providers can help ensure safe and effective glycemic control for their patients.