How to convert from Lantus (insulin glargine) to NPH (neutral protamine Hagedorn) insulin?

From the Guidelines

To convert from Lantus to NPH insulin, the total daily NPH dose should be 80% of the current Lantus dose, divided into two daily doses, with 2/3 given before breakfast and 1/3 given before dinner, as recommended by the most recent guidelines 1. When converting from Lantus to NPH, it's essential to consider the different pharmacokinetic profiles of these insulins. Lantus is a long-acting insulin with a relatively flat 24-hour profile and no pronounced peak, while NPH has an onset of 1-2 hours, peaks at 4-8 hours, and lasts 12-18 hours.

• The total daily NPH dose is calculated as 80% of the current Lantus dose, which may require adjustments based on individual needs 1.
• The NPH dose should be divided into two daily doses, with 2/3 given before breakfast and 1/3 given before dinner, to minimize the risk of hypoglycemia and optimize blood glucose control 1.
• Close blood glucose monitoring is crucial during the transition period, with adjustments made every 2-3 days based on patterns, to ensure optimal dosing and minimize the risk of hypoglycemia or hyperglycemia 1.
• Patients should be aware that NPH requires more consistent meal timing and may have a higher risk of hypoglycemia during peak action times, and consultation with a healthcare provider is necessary before making this switch to ensure appropriate dosing and monitoring.

From the FDA Drug Label

When switching from: Once-daily NPH insulin to once-daily Insulin Glargine, the recommended starting Insulin Glargine dosage is the same as the dosage of NPH that is being discontinued Twice-daily NPH insulin to once-daily Insulin Glargine, the recommended starting Insulin Glargine dosage is 80% of the total NPH dosage that is being discontinued

To convert from Lantus (another name for Insulin Glargine) to NPH, the label does not provide direct guidance. However, it provides guidance for converting from NPH to Lantus.

• For once-daily NPH to Lantus, the dosage is the same.
• For twice-daily NPH to Lantus, the dosage is 80% of the total NPH dosage. Since the conversion from Lantus to NPH is the reverse, it can be inferred that:
• For once-daily Lantus to NPH, the dosage would be the same.
• For once-daily Lantus to twice-daily NPH, the total NPH dosage would be 125% of the Lantus dosage, divided into two doses. However, this is not explicitly stated in the label, and the evidence is unclear. Therefore, the conversion should be done under medical supervision with close monitoring of blood glucose levels. 2

From the Research

Conversion from Lantus to NPH

• The conversion from Lantus (insulin glargine) to NPH insulin is a common practice in diabetes management, and several studies have compared the efficacy and safety of these two insulins 3, 4, 5, 6, 7.
• According to a study published in 2019, insulin glargine U100 improved glycemic control and reduced nocturnal hypoglycemia in patients with type 2 diabetes mellitus and chronic kidney disease stages 3 and 4, compared to NPH insulin 3.
• Another study published in 2017 found that insulin glargine 100U/mL had a similar efficacy to NPH insulin in people with type 2 diabetes, but with a lower risk of overall and nocturnal hypoglycemia 4.
• A randomized clinical trial published in 2015 found that insulin glargine and NPH insulin were equally effective in managing glucocorticoid-induced hyperglycemia in hospitalized patients with type 2 diabetes and respiratory disease 5.
• A meta-analysis published in 2008 found that insulin glargine and NPH insulin had similar glucose-lowering effects, but insulin glargine was associated with less patient-reported hypoglycemia and slightly less weight gain 6.
• Another study published in 2008 found that insulin glargine resulted in a reduced rate of severe hypoglycemic events compared to NPH insulin, with a potential cost savings of 40% to 60% 7.

Key Considerations

• When converting from Lantus to NPH, it is essential to consider the individual patient's needs and medical history, as well as the potential differences in efficacy and safety between the two insulins.
• The dosage and administration of NPH insulin may need to be adjusted to achieve optimal glycemic control, and patients should be closely monitored for signs of hypoglycemia or other adverse effects.
• Healthcare providers should consult the relevant clinical guidelines and studies to inform their decision-making when converting patients from Lantus to NPH insulin.