What comparable basal insulin should I prescribe for a patient who can no longer obtain coverage for insulin degludec (Tresiba)?

Comparable Basal Insulin Alternative to Tresiba

When Tresiba (insulin degludec) is no longer covered, prescribe NPH insulin as the most cost-effective basal insulin alternative, recognizing that it will require twice-daily dosing and carries a higher risk of hypoglycemia compared to long-acting analogs. 1

Primary Alternative: NPH Insulin

NPH insulin remains the recommended first-line alternative when long-acting analogs lose coverage, despite substantial price increases in insulin products over the past decade 1. NPH can achieve equivalent glycemic control to Tresiba when dosed appropriately, though it requires different administration patterns 1.

Key Differences from Tresiba

• Dosing frequency: NPH typically requires twice-daily administration (before breakfast and at bedtime) rather than Tresiba's once-daily dosing to approximate 24-hour coverage 1
• Hypoglycemia risk: NPH carries a significantly higher risk of nocturnal hypoglycemia compared to long-acting analogs like Tresiba due to its pronounced peak effect 1, 2
• Action profile: Unlike Tresiba's ultra-long peakless profile (>42 hours duration), NPH has a distinct peak at 4-10 hours and duration of 12-18 hours 2, 3

Conversion Protocol

Initial Dose Calculation

• Start with unit-for-unit conversion from the total daily Tresiba dose, then split into two NPH doses 1
• For patients in very tight glycemic control or at high hypoglycemia risk, consider reducing the initial total dose by 10-20% when switching from Tresiba to NPH 1

Dosing Schedule

• Administer NPH twice daily: before breakfast and at bedtime 1
• The twice-daily schedule is essential—once-daily NPH will NOT provide adequate 24-hour coverage for most patients 1

Example Conversion

If a patient takes 30 units of Tresiba once daily:

• Start with 15 units NPH before breakfast and 15 units NPH at bedtime
• For high-risk patients: Consider 12-14 units twice daily (20% reduction)

Monitoring Requirements After Switching

Intensify glucose monitoring during the first 2-4 weeks after switching insulin types 1. This critical period allows identification of hypoglycemia patterns and inadequate coverage.

• Check fasting glucose daily to titrate the bedtime NPH dose 1
• Check pre-dinner glucose to assess morning NPH adequacy 1
• Adjust doses by 10-15% or 2-4 units once or twice weekly until fasting glucose targets (80-130 mg/dL) are met 1

Critical Pitfalls to Avoid

Dosing Errors

• Never assume once-daily NPH will provide adequate 24-hour coverage—most patients require twice-daily dosing 1
• Do not mix NPH with other insulins if the patient is also on rapid-acting analogs; these should be given as separate injections 1

Medication Management Mistakes

• Avoid switching multiple diabetes medications simultaneously, as this makes it difficult to identify the cause of glycemic changes 1
• Do not discontinue rapid-acting mealtime insulin when switching basal insulins—basal insulin only addresses fasting/between-meal glucose 1

Meal Timing Considerations

• Maintain consistent meal timing and carbohydrate content due to NPH's pronounced peak effect 1
• Irregular eating patterns increase hypoglycemia risk with NPH compared to Tresiba's flat profile 4, 5

Alternative Strategy: GLP-1 Receptor Agonist Addition

Before intensifying insulin further, consider adding a GLP-1 receptor agonist (semaglutide, dulaglutide, liraglutide) for patients using basal insulin at high doses (>0.5 units/kg/day) with inadequate control 1.

Advantages of GLP-1 RA Addition

• Reduces insulin requirements while improving glycemic control 1
• Promotes weight loss rather than weight gain 1
• Lowers hypoglycemia risk compared to insulin intensification 1
• May allow reduction of basal insulin dose, potentially making NPH's limitations more manageable 6

Other Long-Acting Analog Alternatives

If insurance covers other long-acting analogs but not Tresiba specifically:

Insulin Glargine (Lantus, Basaglar, Toujeo)

• U-100 glargine (Lantus/Basaglar): Once-daily dosing with 24-hour duration, lower hypoglycemia risk than NPH 1, 2
• U-300 glargine (Toujeo): Longer duration than U-100 glargine with lower hypoglycemia risk, particularly for nocturnal events 6
• Conversion: Unit-for-unit from Tresiba to glargine U-100; U-300 may require 10-18% higher total daily dose 6

Insulin Detemir (Levemir)

• May require once-daily or twice-daily dosing depending on duration of coverage 6, 7
• When converting from glargine to detemir, total daily detemir dose should be approximately 38% higher than glargine dose 8
• Less suitable than glargine as Tresiba replacement due to shorter duration 7

Patient Education Essentials

Hypoglycemia Recognition

• Emphasize increased nocturnal hypoglycemia risk with NPH compared to Tresiba 1, 2
• Review symptoms: shakiness, sweating, confusion, rapid heartbeat
• Keep fast-acting carbohydrates readily available at bedside 1

Injection Technique

• Proper resuspension of NPH is critical—roll vial gently 10 times before drawing dose
• NPH appears cloudy; if it remains clear or has clumps after mixing, do not use
• Rotate injection sites to prevent lipohypertrophy 1

Timing Consistency

• Administer NPH at consistent times daily, particularly the bedtime dose 1
• Coordinate meal timing with NPH peaks (4-10 hours post-injection) 2

When NPH Is Insufficient

If NPH fails to achieve glycemic targets despite optimization:

• When basal insulin exceeds 0.5 units/kg/day, consider adding prandial insulin rather than continuing to escalate basal insulin alone 6, 1
• Reassess insurance coverage for long-acting analogs, as clinical necessity (recurrent severe hypoglycemia) may justify prior authorization 1
• Consider patient assistance programs from manufacturers for long-acting analogs 1