Conversion from Basaglar to Tresiba: 22 Units
Start with 22 units of Tresiba when converting from 22 units of Basaglar, using a unit-for-unit conversion approach.
Recommended Conversion Strategy
The most straightforward and evidence-based approach is a 1:1 (unit-for-unit) conversion from Basaglar (insulin glargine U-100) to Tresiba (insulin degludec). For your patient taking 22 units of Basaglar, initiate 22 units of Tresiba 1.
Supporting Evidence
Real-world data demonstrates that when converting from insulin glargine U-100 to insulin degludec, basal insulin dose requirements remain essentially unchanged. A study of 39 patients transitioning from glargine U-100 to degludec showed no significant difference in insulin doses between baseline and follow-up (p = 0.56), indicating that empiric dose adjustments are not routinely necessary 1.
Additional observational data from 266 patients (172 with type 1 diabetes, 96 with type 2 diabetes) provides conversion equations. For patients on once-daily basal insulin, the relationship is: Degludec dose = 3.39 + 0.78 × (baseline glargine dose). Using this formula for 22 units of Basaglar: 3.39 + (0.78 × 22) = 20.5 units 2. This suggests a slightly lower dose may be needed, though the difference is modest.
Clinical Implementation
- Initial dose: Start with 22 units of Tresiba (unit-for-unit conversion)
- Timing: Administer once daily at the same time each day 3
- Monitoring: Check fasting plasma glucose closely during the first 2-4 weeks
- Titration: Adjust by 2 units every 3 days based on fasting glucose to reach individualized glycemic targets 4
Important Caveats
Monitor for hypoglycemia: While degludec has a longer half-life (approximately 25 hours) and more stable pharmacokinetics than glargine, the conversion equations suggest some patients may require 10-20% less basal insulin with degludec 2. If hypoglycemia occurs without clear cause, reduce the dose by 10-20% 4.
Consider slight dose reduction in specific populations: If your patient has a history of hypoglycemia or hypoglycemia unawareness, consider starting at 20 units (approximately 10% reduction) and titrating up as needed.
Prescribe glucagon: Ensure the patient has access to emergency glucagon for severe hypoglycemia 4.
Why Unit-for-Unit Conversion Works
Tresiba (degludec) and Basaglar (glargine U-100) have comparable glucose-lowering effects when dosed appropriately. Clinical trials demonstrate non-inferiority between these insulins at clinically titrated doses 3. The ultra-long duration of action of degludec (>42 hours) provides more consistent day-to-day absorption compared to glargine, but this translates to improved glycemic stability rather than requiring dramatically different dosing 5.