What is the alternative insulin regimen for a patient with hyperglycemia, currently on Lantus (insulin glargine) 16 units, when Lantus is not available, with a correction scale of 18-20-18 mmol/L?

Alternative Insulin Regimen When Lantus is Unavailable

Switch to NPH insulin or insulin detemir as the basal insulin replacement, using approximately the same total daily dose (16 units), but administered differently based on the chosen alternative. 1, 2

Immediate Replacement Options

Option 1: NPH Insulin (Most Accessible Alternative)

• Start with NPH 8 units twice daily (morning and bedtime), totaling 16 units per day to match the current Lantus dose 1, 2
• NPH requires twice-daily dosing due to its shorter duration of action (12-16 hours vs. 24 hours for Lantus) 3, 4
• Administer 2/3 of the dose (approximately 10-11 units) in the morning and 1/3 (approximately 5-6 units) at bedtime, or split evenly as 8 units twice daily initially 1
• Critical timing: Give morning dose with breakfast and evening dose at bedtime to match NPH's peak action with meal times and minimize nocturnal hypoglycemia risk 1, 4

Option 2: Insulin Detemir (If Available)

• Start with insulin detemir 8 units twice daily (morning and bedtime), totaling 16 units per day 2, 3
• Detemir has a duration of action of approximately 12-20 hours, often requiring twice-daily dosing like NPH 3, 4
• Alternatively, start with 16 units once daily at bedtime and assess if twice-daily dosing is needed based on fasting glucose control 3
• Detemir offers less within-patient variability and lower nocturnal hypoglycemia risk compared to NPH 3, 4

Option 3: Insulin Degludec (Ultra-Long-Acting Alternative)

• Start with insulin degludec 16 units once daily at any consistent time of day 5
• Degludec has an ultra-long duration of action (>42 hours) and can be administered at varying times if needed 5
• This option provides the most similar dosing convenience to Lantus with once-daily administration 5

Maintaining the Correction Scale

• Continue the correction scale insulin (18-20-18 units) with rapid-acting insulin before meals or every 6 hours as currently prescribed 1
• The correction scale addresses acute hyperglycemic excursions and operates independently from basal insulin adjustments 2
• Use rapid-acting insulin analogs (insulin aspart, lispro, or glulisine) or regular insulin for correction doses 1

Titration Protocol After Switching

For NPH or Detemir:

• Increase the dose by 2-4 units every 3 days based on fasting blood glucose readings until reaching target of 4.4-7.2 mmol/L (80-130 mg/dL) 1, 2, 6
• If fasting glucose ≥10 mmol/L (≥180 mg/dL), increase by 4 units 2
• If fasting glucose 7.8-10 mmol/L (140-179 mg/dL), increase by 2 units 2, 6
• Monitor for hypoglycemia and reduce dose by 10-20% if blood glucose <4.0 mmol/L (<72 mg/dL) occurs 1, 2

For Degludec:

• Follow the same titration algorithm as above, but wait at least 3-7 days between dose adjustments due to its ultra-long half-life 2, 5

Critical Pitfalls to Avoid

• Do not use the same once-daily dosing schedule with NPH that was used for Lantus—NPH requires twice-daily administration to provide adequate 24-hour basal coverage 1, 3
• Do not mix NPH with rapid-acting insulin analogs in the same syringe unless using specifically approved premixed formulations 1
• Monitor for increased nocturnal hypoglycemia risk with NPH compared to Lantus, particularly in the first 2-4 weeks after switching 4, 7
• Expect slightly higher fasting glucose variability with NPH compared to Lantus due to its peak action profile 3, 4, 7
• Do not delay dose titration—adjust every 3 days based on fasting glucose readings to achieve glycemic targets promptly 1, 2, 6

Monitoring Requirements

• Daily fasting blood glucose monitoring is essential during the transition period and titration phase 2, 6
• Assess for nocturnal hypoglycemia by checking blood glucose at 2-3 AM if symptoms occur 4, 7
• Continue pre-meal and 2-hour postprandial glucose monitoring to guide correction scale insulin use 1
• Reassess the regimen after 3-6 months with HbA1c measurement 1, 2