Initiating and Titrating Insulin Degludec (Tresiba) in Adults with Diabetes
Initial Dosing
For insulin-naïve adults with type 2 diabetes, start insulin degludec at 10 units once daily at any time of day. 1 This is the FDA-approved starting dose and aligns with guideline recommendations for basal insulin initiation. 2, 3 Alternatively, you can use weight-based dosing at 0.1–0.2 units/kg/day, which for most adults translates to 10–20 units daily. 2, 4, 3
For insulin-naïve adults with type 1 diabetes, calculate the total daily insulin requirement as 0.2–0.4 units/kg/day, then allocate approximately one-third to one-half of this total to insulin degludec as the basal component. 1 The remainder should be given as rapid-acting insulin divided among meals. 1 For a metabolically stable adult with type 1 diabetes, a typical starting point is 0.5 units/kg/day total, with roughly 40–50% (0.2–0.25 units/kg/day) given as degludec. 2, 3
Switching from Other Insulins
When converting adults from another basal insulin to degludec, start degludec at the same unit dose as the previous long- or intermediate-acting insulin. 1 For pediatric patients (≥1 year), reduce to 80% of the prior basal dose to minimize hypoglycemia risk. 1
Titration Protocol
Increase the degludec dose by 2 units every 3–4 days if fasting glucose is 140–179 mg/dL, and by 4 units every 3–4 days if fasting glucose is ≥180 mg/dL. 2, 4, 3, 1 The target fasting glucose range is 80–130 mg/dL. 2, 4, 3 The FDA label specifies 3–4 days between adjustments, which is consistent with ADA guidelines. 1, 2
If unexplained hypoglycemia (glucose <70 mg/dL) occurs, immediately reduce the degludec dose by 10–20%. 2, 4, 3 Treat the hypoglycemia with 15 grams of fast-acting carbohydrate. 2, 4
Patient Self-Titration
Equip patients with self-titration algorithms based on daily fasting glucose monitoring. 2, 4, 3 Studies demonstrate that patient-directed dose adjustments improve glycemic control compared to physician-only titration. 2, 3
Monitoring Requirements
Check fasting glucose daily during the titration phase. 2, 4, 3 Once stable, continue monitoring at least several times weekly to guide ongoing adjustments. 2, 3 Reassess HbA1c every 3 months during active titration. 2, 4
Critical Threshold: Recognizing Over-Basalization
When degludec approaches 0.5 units/kg/day without achieving glycemic targets, stop further basal escalation and add prandial insulin or a GLP-1 receptor agonist instead. 2, 4, 3 Clinical signals of over-basalization include:
- Basal dose >0.5 units/kg/day with unmet HbA1c goal 2, 4
- Bedtime-to-morning glucose differential ≥50 mg/dL 2, 4
- Recurrent hypoglycemia despite overall hyperglycemia 2, 4
- High glucose variability throughout the day 2, 4
Continuing to escalate basal insulin beyond this threshold leads to increased hypoglycemia risk without improving control. 2, 4
Adding Prandial Insulin (Type 2 Diabetes)
If HbA1c remains above target after 3–6 months of optimized basal insulin (fasting glucose 80–130 mg/dL), add rapid-acting insulin before the largest meal. 2, 4, 3 Start with 4 units or 10% of the current basal dose. 2, 4, 5 Titrate prandial doses by 1–2 units every 3 days based on 2-hour postprandial glucose, targeting <180 mg/dL. 2, 4, 5
Combination Therapy
Continue metformin at the maximum tolerated dose (up to 2,000–2,550 mg daily) when initiating or intensifying degludec. 2, 4, 3 Metformin reduces total insulin requirements by 20–30% and provides superior glycemic control compared to insulin alone. 2, 4 Consider discontinuing sulfonylureas when advancing beyond basal-only insulin to prevent hypoglycemia. 2, 4
When basal insulin exceeds 0.5 units/kg/day, consider adding a GLP-1 receptor agonist instead of prandial insulin. 2, 4 This combination provides comparable postprandial control with less hypoglycemia and weight gain. 2, 4
Unique Advantages of Degludec
Degludec's ultra-long duration of action (>42 hours) provides more stable glucose control with reduced day-to-day variability compared to insulin glargine. 6, 7, 8 This translates to significantly lower rates of nocturnal hypoglycemia—25–58% reduction in type 1 diabetes and 25–29% reduction in type 2 diabetes compared to glargine. 9, 7, 8
Adults can inject degludec at any time of day, and the timing can vary from day to day (as long as ≥8 hours elapse between doses). 1, 6 This flexibility is unique to degludec and can improve adherence. 6, 8 Pediatric patients should inject at the same time daily. 1
Dosing Formulations
Degludec is available in two concentrations: 1
- U-100 (100 units/mL): FlexTouch pen (delivers 1–80 units) and 10 mL vial
- U-200 (200 units/mL): FlexTouch pen (delivers 2–160 units in 2-unit increments)
Do not perform dose conversion between concentrations—the dose window shows the actual units to deliver. 1 The U-200 pen is recommended for most adults with type 2 diabetes requiring higher doses, while U-100 is preferred for type 1 diabetes and patients needing smaller dose adjustments. 6
Common Pitfalls to Avoid
Never delay insulin initiation in patients not achieving glycemic goals with oral medications alone. 2, 4, 3 Prolonged hyperglycemia increases complication risk. 2, 4
Do not discontinue metformin when starting degludec unless contraindicated. 2, 4, 3 This leads to higher insulin requirements and greater weight gain. 2, 4
Avoid continuing to escalate degludec beyond 0.5–1.0 units/kg/day without addressing postprandial hyperglycemia. 2, 4 This causes over-basalization with increased hypoglycemia and suboptimal control. 2, 4
Never share degludec pens, needles, or syringes between patients, even if the needle is changed. 1 This poses a risk for transmission of blood-borne pathogens. 1
Special Populations
For hospitalized patients on high-dose home insulin (≥0.6 units/kg/day), reduce the total daily dose by 20% upon admission. 4, 3 For elderly patients (>65 years), those with renal impairment, or poor oral intake, use lower starting doses (0.1–0.25 units/kg/day). 4
In CKD stage 5, reduce total daily insulin by 50% for type 2 diabetes and 35–40% for type 1 diabetes. 4 Insulin clearance decreases with declining kidney function, requiring closer hypoglycemia monitoring. 4