What is the recommended dosing, titration, administration, and contraindications for insulin degludec 100 U/mL as basal insulin therapy?

Insulin Degludec 100 U/mL: Dosing, Titration, Administration, and Contraindications

Initial Dosing

For insulin-naïve patients with type 2 diabetes, start insulin degludec at 10 units once daily. 1, 2, 3, 4, 5 This is the standard recommended starting dose across all major guidelines and the FDA label.

For patients with type 1 diabetes, the recommended starting dose is approximately one-third to one-half of the total daily insulin requirement, with the remainder given as short-acting insulin divided among meals 5. As a general rule, calculate 0.2–0.4 units/kg of body weight as the initial total daily insulin dose for insulin-naïve type 1 diabetes patients 5.

Special Populations Requiring Lower Starting Doses

• Elderly patients (>65 years): Start with 0.1–0.25 units/kg/day to reduce hypoglycemia risk 2
• Renal impairment (eGFR <60 mL/min/1.73 m²): Begin with 0.1–0.25 units/kg/day and increase glucose monitoring 2
• Hospitalized patients with limited oral intake: Use 0.1–0.25 units/kg/day as basal insulin only 2
• Patients on high-dose home insulin (≥0.6 units/kg/day): Reduce total daily dose by 20% upon admission 2

Switching from Other Insulins

Adults with type 1 or type 2 diabetes: Start degludec at the same unit dose as the total daily long- or intermediate-acting insulin 5.

Pediatric patients ≥1 year with type 1 or type 2 diabetes: Start degludec at 80% of the total daily long- or intermediate-acting insulin dose to minimize hypoglycemia risk 5.

When switching from glargine U-100/U-300, similar doses are typically required 3. Dosage adjustments are recommended when switching to minimize hypoglycemia risk 5.

Titration Protocol

Increase the dose by 2 units every 3 days if fasting glucose is 140–179 mg/dL 1, 2, 3.

Increase the dose by 4 units every 3 days if fasting glucose is ≥180 mg/dL 1, 2, 3.

Target fasting glucose: 80–130 mg/dL (4.4–7.2 mmol/L) 1, 2, 3, 6.

If any unexplained hypoglycemia (glucose <70 mg/dL) occurs, immediately reduce the dose by 10–20% rather than waiting for the next scheduled adjustment 1, 2, 3.

Critical Threshold: When to Stop Basal Escalation

Cease further basal insulin increases once the dose reaches 0.5–1.0 units/kg/day without achieving target glucose. At this point, add prandial insulin or a GLP-1 receptor agonist instead of continuing to escalate basal insulin 1, 2, 3. Clinical signals of "over-basalization" include:

• Basal dose >0.5 units/kg/day 1, 2
• Bedtime-to-morning glucose differential ≥50 mg/dL 1, 2
• Recurrent hypoglycemia despite overall hyperglycemia 1, 2
• Marked glucose variability throughout the day 1, 2

Administration

Administer insulin degludec once daily at any time of day, but maintain consistency in timing 5, 7, 8. The unique ultra-long duration of action (half-life exceeding 25 hours) allows for flexible dosing 7, 8, 9.

For adults who miss a dose: Inject the daily dose during waking hours upon discovering the missed dose, ensuring at least 8 hours have elapsed between consecutive injections 5.

For pediatric patients who miss a dose: Contact healthcare provider for guidance and monitor blood glucose more frequently until the next scheduled dose 5.

Injection Technique

• Use the shortest needles available (4-mm pen needles or 6-mm syringe needles) as first-line choice—they are safe, effective, and less painful 6
• Avoid intramuscular injections, especially with long-acting insulins, as severe hypoglycemia may result 6
• Rotate injection sites properly to prevent lipohypertrophy, which distorts insulin absorption 6
• Do not inject into areas of lipohypertrophy or localized cutaneous amyloidosis 5
• If switching injection sites from affected to unaffected areas, closely monitor for hypoglycemia 5

Available Formulations

• 100 units/mL (U-100): 3 mL FlexTouch prefilled pen 5
• 100 units/mL (U-100): 10 mL multiple-dose vial 5
• 200 units/mL (U-200): 3 mL FlexTouch prefilled pen 5

Never share FlexTouch pens, needles, or syringes between patients, even if the needle is changed, due to risk of blood-borne pathogen transmission 5.

Monitoring Requirements

• Daily fasting glucose checks during active titration 1, 2, 3
• Reassess basal dose every 3 days while titrating 2
• HbA1c measurement every 3 months during intensive titration 2
• Assess adequacy of insulin dose at every clinical visit 1, 3

Combination Therapy

Continue metformin (up to 2,000–2,550 mg daily) throughout basal insulin therapy. Metformin lowers total insulin requirements by 20–30% and yields superior glycemic control compared to insulin alone 1, 2, 6.

For patients with type 1 diabetes, degludec must be used concomitantly with short-acting insulin 5, 6. Typically, 50–60% of total daily insulin is given as prandial insulin, with 40–50% as basal 1, 2.

When adding prandial insulin to type 2 diabetes patients on degludec, start with 4 units before the largest meal or 10% of the basal dose 1, 3, 10.

Contraindications

Insulin degludec is contraindicated in the following situations:

• During episodes of hypoglycemia 5
• In patients with hypersensitivity to insulin degludec or any excipients 5

Special Clinical Situations

Perioperative Management

Administer 60–80% of the usual degludec dose on the day of surgery 4. For patients on NPH insulin, give 50% of the usual dose 2.

Continuous Enteral Feeding

For patients receiving enteral feedings who require basal insulin, start with 10 units of insulin degludec daily 4, 5. Degludec can be administered once daily as the basal component 4.

Acute Illness or Hospitalization

Make dose adjustments during acute illness to minimize risk of hypoglycemia or hyperglycemia 5. For hospitalized patients, consider the reduced starting doses mentioned above for high-risk populations 2.

Steroid-Induced Hyperglycemia

Consider morning dosing of basal insulin for steroid-induced hyperglycemia rather than bedtime administration 3.

Hypoglycemia Management

Hypoglycemia is the most common adverse reaction of insulin degludec 5. The long-acting effect may delay recovery from hypoglycemia compared to shorter-acting insulins 5.

Treat glucose <70 mg/dL immediately with 15 g of fast-acting carbohydrate, recheck in 15 minutes, and repeat if needed 1, 2. Patients should carry at least 15 g of carbohydrate at all times 4.

Risk factors for hypoglycemia include:

• Intensity of glycemic control 5
• Changes in meal patterns, physical activity, or renal/hepatic function 5
• Concomitant medications (e.g., beta-blockers) 5
• Longstanding diabetes or diabetic neuropathy 5

Document all hypoglycemic episodes (blood glucose <70 mg/dL) and adjust the treatment plan accordingly 3.

Common Pitfalls to Avoid

• Do not delay insulin initiation in patients failing to meet glycemic goals with oral agents—prolonged hyperglycemia increases complication risk 1, 2
• Never continue escalating basal insulin beyond 0.5–1.0 units/kg/day without addressing postprandial hyperglycemia 1, 2
• Avoid therapeutic inertia—reassess and modify insulin doses regularly every 3–6 months 3
• Never use sliding-scale insulin alone without basal coverage 3
• Do not abruptly discontinue oral medications when starting insulin therapy 6
• Avoid intramuscular injections of long-acting insulins 6

Advantages of Insulin Degludec

The ultra-long duration of action (>24 hours) with a peakless, steady-state profile provides 7, 8, 9:

• Lower risk of nocturnal hypoglycemia compared to insulin glargine 7, 8, 9
• Flexibility in dosing time from day to day while maintaining efficacy 7, 8, 9
• Highly consistent glucose-lowering effect with minimal injection-to-injection variability 8, 9
• Potential for improved adherence in patients with unpredictable schedules 7, 9