What is the recommended dose of Lantus (insulin glargine) when transitioning from NPH (neutral protamine Hagedorn) insulin 22 units twice daily?

Transitioning from NPH 22 units bid to Lantus

When transitioning from NPH insulin 22 units twice daily (total 44 units) to insulin glargine (Lantus), start with 80% of the total daily NPH dose as a single daily dose of Lantus, which would be approximately 35 units once daily. 1

Conversion Rationale and Process

• The 80% conversion factor (reducing total daily dose by 20%) is recommended when switching from twice-daily NPH to once-daily Lantus to reduce the risk of hypoglycemia during the transition 1
• Lantus provides a relatively constant basal level of circulating insulin with no pronounced peak, unlike NPH which has a more variable action profile 2
• Lantus can be administered at any time of day, but should be given at the same time each day for consistent effect 3

Dosage Titration Protocol

• After initiating Lantus at 35 units once daily, set a fasting plasma glucose (FPG) target based on individual goals 1
• Follow an evidence-based titration algorithm: increase by 2 units every 3 days until reaching the FPG target without hypoglycemia 1
• If hypoglycemia occurs, determine the cause; if no clear reason is identified, reduce the dose by 10-20% 1
• Assess the adequacy of the basal insulin dose at each follow-up visit 1

Advantages of Lantus over NPH

• Lantus provides more consistent 24-hour coverage without pronounced peaks, resulting in more stable glucose levels 2
• Studies show reduced risk of hypoglycemia with Lantus compared to NPH insulin, particularly nocturnal hypoglycemia (26% reduction in nocturnal and 46% reduction in severe hypoglycemia) 4
• The smoother action profile of Lantus may facilitate more aggressive insulin treatment to reach HbA1c targets 4

Special Considerations

• If the patient experiences persistent hypoglycemia despite dose adjustments, consider splitting the Lantus dose into twice-daily administration 5
• For patients with significant postprandial hyperglycemia, Lantus alone will not be sufficient - rapid-acting insulin at mealtimes may be needed 3
• Monitor blood glucose more frequently during the transition period, especially in the first 1-2 weeks 1

Common Pitfalls to Avoid

• Do not mix Lantus with other insulins in the same syringe as this may alter its action profile 3
• Avoid abrupt changes in injection sites, as absorption rates may differ between sites 1
• Be aware that some patients may require a higher percentage of their previous NPH dose if they were experiencing frequent hyperglycemia on their previous regimen 6
• If glycemic control worsens after transition, consider whether the total insulin dose needs adjustment or if prandial coverage is needed 1

Alternative Approaches

• If once-daily Lantus doesn't provide adequate 24-hour coverage, splitting the dose to twice daily may be beneficial for some patients 5
• Some studies suggest that increasing the Lantus dose to approximately 48% of the total daily insulin requirement (when used in basal-bolus regimens) may optimize glycemic control 6