What is the conversion dose from insulin Glargine (insulin glargine) to Tresiba (insulin degludec) for a patient?

Converting from Insulin Glargine to Tresiba (Insulin Degludec)

Direct Conversion Ratio

Convert insulin glargine to insulin degludec using a 1:1 unit-for-unit dose, maintaining the same total daily basal insulin dose. 1, 2

Conversion Protocol

• Administer the first dose of Tresiba at the same unit dose as the previous glargine regimen 1
• The conversion can be done directly without a transition period, as both insulins provide basal coverage 2
• Tresiba has a longer duration of action (>42 hours) compared to glargine (approximately 24 hours), which provides more stable glucose-lowering effects 1, 2

Key Pharmacokinetic Differences to Anticipate

• Tresiba reaches maximum concentration (tmax) at 10-12 hours with a half-life of 17-21 hours, roughly double the duration of glargine 2
• Tresiba demonstrates a flatter, more stable glucose-lowering profile with significantly less within-patient day-to-day variability compared to glargine 1
• The ultra-long action of Tresiba (>42 hours) allows for flexible dosing timing, though consistent daily administration is still recommended 1

Expected Clinical Outcomes After Conversion

• Similar glycemic control (A1C) compared to glargine, but with lower risk of nocturnal hypoglycemia 1
• The more predictable pharmacodynamic profile of Tresiba may reduce glucose variability 1, 2
• Full steady-state insulin levels with Tresiba are achieved after 2-3 days of daily dosing due to its long half-life 2

Monitoring Requirements Post-Conversion

• Monitor fasting blood glucose daily during the first week after conversion 3
• Assess for hypoglycemia, particularly nocturnal episodes, which should decrease compared to glargine 1
• Titrate the Tresiba dose by 2-4 units every 3 days based on fasting glucose patterns if needed to reach target of 80-130 mg/dL 3, 4

Special Considerations

• If the patient was on twice-daily glargine due to inadequate 24-hour coverage, convert to once-daily Tresiba at the total combined daily dose, as Tresiba's ultra-long action typically provides superior 24-hour coverage 1, 2
• Tresiba is available in a U-200 formulation for patients requiring high basal insulin doses, with pharmacokinetics similar to U-100 5
• Unlike glargine, Tresiba can be mixed with rapid-acting insulin aspart in coformulation products (Ryzodeg), though this is a separate consideration from basal insulin conversion 1, 2

Critical Pitfall to Avoid

• Do not reduce the initial Tresiba dose "to be safe" - the 1:1 conversion is evidence-based and reducing the dose will result in hyperglycemia during the transition 1
• Do not expect immediate changes in glucose control on day 1, as Tresiba requires 2-3 days to reach steady state 2