What is the recommended dosing of Lantus (insulin glargine) when initiating it in a patient already on Humalog 75/25 (insulin lispro protamine/insulin lispro)?

Lantus Dosing When Transitioning from Humalog 75/25

When transitioning a patient from Humalog 75/25 (insulin lispro protamine/insulin lispro) to a regimen that includes Lantus (insulin glargine), start Lantus at 80% of the total daily dose of the premixed insulin.

Initial Dosing Recommendations

• When switching from premixed insulin like Humalog 75/25 to once-daily Lantus, the recommended starting Lantus dosage is 80% of the total daily premixed insulin dose 1
• For example, if a patient is taking 50 units of Humalog 75/25 daily (25 units twice daily), the initial Lantus dose would be 40 units once daily 1
• Lantus should be administered subcutaneously once daily at any time of day, but at the same time every day to maintain consistent blood glucose control 1

Titration and Monitoring

• After initiating Lantus, increase the frequency of blood glucose monitoring to assess the need for dose adjustments 1
• Adjust Lantus dosage based on fasting blood glucose levels, targeting 90-150 mg/dL for most patients 2
• Consider using a simple titration algorithm: increase by 2 units if fasting glucose is consistently above target for 2-3 days, and decrease by 2-4 units if hypoglycemia occurs 3
• The American Diabetes Association recommends equipping patients with an algorithm for self-titration of insulin doses based on self-monitoring of blood glucose to improve glycemic control 4

Prandial Insulin Considerations

• In patients with type 1 diabetes, Lantus must be used concomitantly with short-acting insulin 1
• For type 2 diabetes patients, assess whether additional prandial insulin coverage is needed based on postprandial glucose readings 5
• If postprandial glucose remains elevated, consider adding rapid-acting insulin before meals or continuing a reduced dose of Humalog 75/25 5

Special Considerations

• Lantus has no peak action time, reducing the risk of hypoglycemia compared to intermediate-acting insulins 6
• Patients with renal impairment (eGFR<60 mL/min/1.73 m²) may require a lower starting dose of approximately 0.114 U/kg/day 7
• Patients with retinopathy may also require a lower starting dose of approximately 0.120 U/kg/day 7
• Women may require a slightly lower starting dose (0.135 U/kg/day) compared to men 7

Common Pitfalls to Avoid

• Never share Lantus SoloStar prefilled pens, insulin syringes, or needles between patients due to risk of blood-borne pathogen transmission 1
• Avoid injecting Lantus into areas of lipodystrophy or localized cutaneous amyloidosis to prevent variable absorption and unpredictable blood glucose levels 1
• Be aware that changes in insulin regimen may affect glycemic control and predispose to hypoglycemia or hyperglycemia 1
• Lantus cannot be mixed with other insulins in the same syringe; separate injections must be used 1

Benefits of Lantus vs. NPH Insulin

• Studies show that insulin glargine is associated with a 46% reduction in severe hypoglycemia risk and 59% reduction in severe nocturnal hypoglycemia compared to NPH insulin 8
• The smooth 24-hour time-action profile of Lantus provides more consistent glycemic control with less glucose variability 9
• More patients achieve target HbA1c levels without confirmed nocturnal hypoglycemia when using Lantus compared to NPH insulin 8