Insulin Glargine Dosing Equivalent to 12 Units of Tresiba
When converting from 12 units of insulin degludec (Tresiba) at bedtime to insulin glargine, a 1:1 conversion ratio should be used, meaning 12 units of insulin glargine would be the equivalent dose.
Understanding Basal Insulin Equivalence
Insulin degludec (Tresiba) and insulin glargine are both long-acting basal insulin analogs with similar clinical effects but different pharmacokinetic profiles:
- Insulin degludec has an ultra-long duration of action (>42 hours)
- Insulin glargine has a long duration of action (20-24 hours)
Conversion Rationale
The American Diabetes Association's Standards of Care guidelines support a unit-to-unit conversion between basal insulins in most cases 1. When switching between basal insulin products:
- Initial doses can typically be converted unit-for-unit
- Subsequent adjustments should be made based on blood glucose monitoring
- A dose reduction of 10-20% may be considered for patients at high risk for hypoglycemia, but this is not routinely necessary for the conversion between degludec and glargine 1
Clinical Considerations
Pharmacokinetic Differences
While the initial conversion uses a 1:1 ratio, be aware of these differences:
- Insulin degludec has a longer duration of action and more stable glucose-lowering profile compared to glargine
- Insulin glargine may have a slightly stronger peak effect, particularly with the U-100 formulation 2
Monitoring After Conversion
After switching from Tresiba to glargine:
- Monitor fasting blood glucose levels closely for 3-7 days
- Expect possible differences in the timing of peak effects
- Be prepared to adjust the glargine dose based on glucose patterns
Timing Considerations
- Insulin degludec (Tresiba) can be administered at any time of day due to its ultra-long duration
- Insulin glargine is typically administered at the same time each day, often at bedtime
- Maintaining consistent timing is more critical with glargine than with degludec
Special Considerations
Hypoglycemia Risk
The DEVOTE trial demonstrated that degludec had a lower risk of severe hypoglycemia compared to glargine U100 2. Therefore, when switching from degludec to glargine:
- Be vigilant for potential increased risk of hypoglycemia
- Consider more frequent blood glucose monitoring initially
- Educate the patient about recognizing and treating hypoglycemia
Dosing Adjustments
If the patient experiences hypoglycemia or significant glycemic variability after conversion:
- Consider reducing the glargine dose by 10-20%
- For patients with significant overnight hypoglycemia, splitting the glargine dose into twice-daily administration might be beneficial in some cases 3
Remember that the goal of basal insulin therapy is to maintain stable glucose levels between meals and overnight while minimizing the risk of hypoglycemia and optimizing overall glycemic control.