NPH Insulin Dosing for Lantus 20 Units
When converting from Lantus 20 units to NPH insulin, the equivalent NPH dose is 20 units, but should be split into a twice-daily regimen with approximately 2/3 (13-14 units) in the morning and 1/3 (6-7 units) in the evening to match NPH's shorter duration of action and pronounced peak. 1
Conversion Principles
- Start with a unit-for-unit conversion (20 units total NPH for 20 units of Lantus) as the initial approach 1
- Split the total NPH dose into a twice-daily regimen due to NPH's shorter duration of action compared to Lantus 1
- Distribute as approximately 2/3 in the morning and 1/3 at bedtime (13-14 units AM, 6-7 units PM) 1
Titration and Adjustment
- After initiating NPH, monitor fasting and pre-meal glucose levels to assess the adequacy of dosing 1
- Increase dose by 2 units every 3 days until reaching fasting plasma glucose target without hypoglycemia 1
- For hypoglycemia, determine the cause; if no clear reason is identified, lower the corresponding dose by 10-20% 1
Special Considerations
- If the patient is taking steroids, consider administering a higher proportion of the NPH dose in the morning to match the pharmacokinetic profile of daily glucocorticoid therapy 2
- NPH has a pronounced peak action compared to the peakless profile of Lantus, which increases risk of hypoglycemia, particularly nocturnal hypoglycemia 3, 4
- Consider patient-specific factors that might require dose adjustments, such as meal patterns, physical activity, and renal/hepatic function 1
Monitoring Recommendations
- Check blood glucose before meals and at bedtime initially to assess the adequacy of the NPH dosing schedule 1
- Pay particular attention to nocturnal glucose levels due to increased risk of nocturnal hypoglycemia with NPH compared to Lantus 4, 5
- Assess for symptoms of hypoglycemia, especially during the peak action of NPH (4-10 hours after injection) 3
Common Pitfalls to Avoid
- Avoid administering the full NPH dose at bedtime as this increases the risk of nocturnal hypoglycemia due to NPH's peak action occurring during sleep 2, 4
- Don't maintain the same once-daily dosing schedule as Lantus; NPH requires twice-daily dosing for optimal glycemic control 1
- Be aware that NPH has greater day-to-day variability in absorption compared to Lantus, which may lead to less predictable glucose control 3, 6