What is the difference between Tresiba (insulin degludec) and Toujeo (insulin glargine U300) in terms of maximum units for a patient with diabetes?

Tresiba vs. Toujeo: Key Differences in Maximum Dosing and Clinical Properties

Tresiba (insulin degludec) is available in U-100 and U-200 concentrations with no maximum dose limit, while Toujeo (insulin glargine U-300) is available only as U-300 with no maximum dose limit, but requires approximately 10-18% higher total daily doses compared to U-100 glargine to achieve equivalent glycemic control. 1, 2

Concentration and Formulation Differences

• Tresiba comes in two concentrations: U-100 (100 units/mL) and U-200 (200 units/mL), both available in prefilled pens only 1, 3
• Toujeo is available exclusively as U-300 (300 units/mL) in prefilled pens, making it three times more concentrated than standard U-100 insulin glargine 1
• The U-200 formulation of Tresiba delivers the same pharmacokinetic profile as U-100 when dosed unit-for-unit, with comparable total and maximum insulin exposure at steady state 3
• U-300 glargine (Toujeo) has modestly lower efficacy per unit administered compared to U-100 glargine, necessitating dose increases of 10-18% when switching from U-100 formulations 1, 2

Pharmacokinetic and Pharmacodynamic Properties

• Tresiba has an ultra-long duration of action exceeding 42 hours after 8 days of once-daily dosing, with a half-life of approximately 25 hours at steady state 3, 4
• Toujeo provides longer duration of action than U-100 glargine (Lantus) but shorter than Tresiba, offering more stable 24-hour coverage with reduced glucose variability 2
• Tresiba reaches steady state after 3-4 days of administration, with maximum concentrations attained at a median of 9 hours post-dose 3
• Tresiba demonstrates 20% within-subject day-to-day variability in total glucose-lowering effect, which is lower than insulin glargine 3, 4
• Both insulins provide peakless profiles, but Tresiba's extended duration offers the most consistent basal coverage 2, 4

Clinical Efficacy and Hypoglycemia Risk

• Tresiba achieves similar glycemic control to insulin glargine but with lower risk of nocturnal hypoglycemia in both type 1 and type 2 diabetes 4, 5
• Toujeo demonstrates significantly lower rates of clinically significant hypoglycemia (<54 mg/dL) compared to U-100 glargine in head-to-head trials 2
• Both longer-acting basal analogs (U-300 glargine and degludec) convey lower hypoglycemia risk compared with U-100 glargine when used in clinical practice 1

Dosing Flexibility and Administration

• Tresiba allows flexible dosing with the ability to adjust injection time by 8-40 hours between doses without compromising glycemic control or safety 4, 6
• Toujeo requires administration at a consistent time each day, similar to standard basal insulin regimens 2
• Tresiba's unique property of miscibility with rapid-acting insulin allows for coformulation products (insulin degludec/insulin aspart), which is not possible with glargine due to its low pH 6

Maximum Dose Considerations

• Neither insulin has an absolute maximum dose limit - both can be titrated based on individual patient needs 1
• The U-200 formulation of Tresiba allows administration of large doses in smaller volumes, theoretically improving absorption for patients requiring high basal insulin doses 4, 7
• U-300 glargine (Toujeo) similarly allows higher doses per volume compared to U-100 formulations 1, 7
• When basal insulin doses exceed 0.5 units/kg/day with A1C remaining above target, consider advancing to combination injectable therapy with GLP-1 receptor agonists or adding prandial insulin rather than continuing to escalate either basal insulin 1, 2

Clinical Selection Criteria

• Choose Tresiba for patients requiring maximum dosing flexibility, those with significant day-to-day schedule variability, or patients needing ultra-long duration of action exceeding 24 hours 4, 7
• Choose Toujeo for patients experiencing recurrent nocturnal hypoglycemia on standard U-100 glargine who need improved hypoglycemia safety profile with longer duration than U-100 but not requiring ultra-long action 2, 7
• Patients requiring large volumes of basal insulin (>80 units daily) may benefit from concentrated formulations of either insulin (Tresiba U-200 or Toujeo U-300) 1, 7

Critical Dosing Caveats

• When switching from U-100 glargine to Toujeo, increase the total daily dose by 10-18% to maintain equivalent glycemic control 1, 2
• When switching between Tresiba formulations (U-100 to U-200 or vice versa), doses can be converted unit-for-unit without adjustment 3
• Signs of overbasalization with either insulin include bedtime-to-morning glucose differential ≥50 mg/dL, increased hypoglycemia, and high glucose variability - in these cases, add GLP-1 receptor agonists or prandial insulin rather than continuing basal escalation 2
• All concentrated insulin formulations (Tresiba U-200, Toujeo U-300) are available only in prefilled pens to minimize the risk of dosing errors 1