Insulin Degludec Classification
Insulin degludec (Tresiba) is an ultra-long-acting basal insulin analog with a duration of action exceeding 42 hours, making it the longest-acting basal insulin currently available. 1, 2
Pharmacological Classification
Insulin degludec is classified as an ultra-long-acting basal insulin analog, distinct from intermediate-acting insulins (NPH) and first-generation long-acting analogs (glargine, detemir). 3
The molecule is produced through recombinant DNA technology in Saccharomyces cerevisiae, with chemical modification where threonine at position B30 is omitted and a C16 fatty acid side-chain is attached. 1
Degludec is available in two concentrations: U-100 (100 units/mL) and U-200 (200 units/mL), with the U-200 formulation designed for patients requiring large basal insulin volumes. 4, 5
Mechanism of Ultra-Long Action
The ultra-long duration results from formation of soluble multi-hexamers in subcutaneous tissue after injection, creating a depot that slowly releases insulin monomers into circulation over more than 42 hours. 1, 6
This absorption mechanism, combined with albumin binding, produces a flat, peakless pharmacodynamic profile with even glucose-lowering effect distributed across all four 6-hour intervals in a 24-hour period. 2
The half-life exceeds 25 hours (compared to ~12 hours for insulin glargine), and steady-state is achieved within 3 days of once-daily administration. 2
Clinical Positioning
The American Diabetes Association recommends insulin degludec as a basal insulin option for both type 1 and type 2 diabetes, providing equivalent glycemic control to glargine but with significantly lower rates of nocturnal hypoglycemia. 7
Degludec demonstrates four times lower day-to-day within-subject variability in glucose-lowering effect compared to insulin glargine (20% coefficient of variation). [2, @12@]
The ultra-long action profile allows flexible once-daily dosing, tolerating day-to-day variation in injection timing without compromising efficacy or safety. 5, 3
Key Distinguishing Features from Other Basal Insulins
Duration of action >42 hours versus 24 hours for U-100 glargine and intermediate duration for U-300 glargine. 4, 1
Superior hypoglycemia safety profile, particularly for nocturnal hypoglycemia in both type 1 and type 2 diabetes compared to insulin glargine. 7, 6
Most stable 24-hour basal coverage among available basal insulins, with the Endocrine Society noting it provides the most consistent basal coverage. 4