What is the recommended NPH dose for a patient on Lantus (insulin glargine) and prednisone, without carb counting?

NPH Insulin Dosing for Patient on Lantus and Prednisone Without Carb Counting

For this 72-year-old male on Lantus 13 units with NPH 8 units and prednisone 30 mg who does not want to carb count, the NPH dose should be converted to a twice-daily regimen with morning-weighted dosing, where the total NPH dose equals approximately 16 units (2/3 morning, 1/3 evening), which is 80% of the current total daily insulin dose. 1

Recommended NPH Dosing Strategy

• Convert to a twice-daily NPH regimen with morning-weighted dosing to better match the hyperglycemic pattern caused by prednisone 1
• Calculate the total daily insulin requirement: 13 units (Lantus) + 8 units (current NPH) + approximately 12 units (average prandial insulin at 4 units per meal) = 33 units 2
• Set the new total NPH dose at approximately 80% of this total = 26 units 2, 1
• Distribute the NPH as follows:
  • Morning dose: 2/3 of total NPH = 17-18 units (before breakfast) 2, 1
  • Evening dose: 1/3 of total NPH = 8-9 units (before dinner or at bedtime) 2, 1

Rationale for This Approach

• Morning-weighted NPH dosing aligns with the hyperglycemic pattern caused by prednisone, which typically peaks 4-8 hours after administration 1
• NPH insulin peaks at 4-6 hours after injection, making it particularly suitable for counteracting steroid-induced daytime hyperglycemia 1
• Patients on once-daily steroids like prednisone experience disproportionate hyperglycemia during the day but often reach target glucose levels overnight 1
• The American Diabetes Association recommends twice-daily NPH with morning-weighted dosing for patients on steroids who don't want to carb count 2, 1

Monitoring and Titration

• Set fasting plasma glucose (FPG) target and monitor blood glucose patterns 2
• Titrate the morning NPH dose if daytime hyperglycemia persists 1
• Increase NPH by 2 units every 3 days until target blood glucose is reached without hypoglycemia 2
• For hypoglycemia, determine the cause; if no clear reason is found, lower the corresponding dose by 10-20% 2

Important Considerations and Pitfalls

• Patients on steroids typically require 40-60% higher insulin doses than their usual requirements 1
• Monitor for nocturnal hypoglycemia, which may occur if the evening NPH dose is too high 2, 1
• If twice-daily NPH proves insufficient, consider adding fixed prandial insulin doses or progressing to a full basal-bolus regimen 2, 1
• Consider the patient's weight (87.5 kg) when evaluating insulin dosing adequacy; doses exceeding 0.5 units/kg/day may indicate the need for adjustment 2

Alternative Approaches if Initial Strategy Fails

• If glycemic control remains suboptimal, consider a self-mixed/split insulin regimen with NPH and fixed doses of rapid-acting insulin 2, 1
• For persistent nocturnal hypoglycemia, consider switching back to a long-acting basal analog with separate fixed prandial dosing 1