How do I transition a patient from Humalog (insulin lispro) 75/25 to Lantus (insulin glargine)?

Transitioning from Humalog 75/25 to Lantus (Insulin Glargine)

When transitioning a patient from Humalog 75/25 to Lantus (insulin glargine), calculate the total daily basal insulin requirement from the premixed insulin and administer Lantus as a once-daily injection, while adding rapid-acting insulin for mealtime coverage. 1, 2

Understanding the Insulin Types

• Humalog 75/25 is a premixed insulin containing 75% insulin lispro protamine suspension (intermediate-acting) and 25% insulin lispro (rapid-acting) 3
• Lantus (insulin glargine) is a long-acting insulin analog that provides a relatively constant basal level of insulin with no pronounced peak for up to 24 hours 4
• The transition requires separating the basal and bolus components currently combined in the premixed insulin 2

Step-by-Step Transition Protocol

Step 1: Calculate Total Daily Basal Insulin Requirement

• Determine the total daily dose (TDD) of Humalog 75/25 currently being administered 1
• Calculate the basal component by taking 75% of the TDD of Humalog 75/25 2
• For example, if patient is on 40 units of Humalog 75/25 total daily (20 units twice daily), the basal component would be 30 units (75% of 40 units) 1

Step 2: Initiate Lantus Dosing

• Start Lantus at 80% of the calculated basal requirement to avoid hypoglycemia during transition 1
• Administer Lantus once daily at the same time each day (typically bedtime) 4
• In our example, the starting Lantus dose would be 24 units (80% of 30 units) 1

Step 3: Add Mealtime Insulin Coverage

• Calculate the bolus component by taking 25% of the TDD of Humalog 75/25 2
• Distribute this as rapid-acting insulin (such as Humalog) before meals 1
• In our example, 10 units (25% of 40 units) would be distributed across meals 1

Step 4: Monitor and Adjust

• Check blood glucose levels frequently during the transition period, especially fasting and 2-hour postprandial levels 2
• Adjust Lantus dose by 2-4 units every 3-4 days based on fasting glucose values 2
• Target fasting blood glucose of 90-150 mg/dL for most patients 2

Special Considerations

• Risk of hypoglycemia: Monitor closely during transition as the pharmacokinetic profiles differ significantly between premixed and basal insulins 4
• Timing: Administer the first Lantus dose in the evening of the day you plan to discontinue Humalog 75/25, giving the last dose of Humalog 75/25 in the morning of that day 1
• HbA1c monitoring: Schedule follow-up within 2-4 weeks to assess glycemic control and make further adjustments 1

Common Pitfalls to Avoid

• Inadequate mealtime coverage: Failing to provide adequate rapid-acting insulin for meals can lead to postprandial hyperglycemia 2
• Dose stacking: Lantus should be given once daily; adding a second dose risks hypoglycemia 4
• Abrupt transition: A gradual transition with close monitoring reduces the risk of glycemic variability 1
• Forgetting correction doses: Include instructions for correction doses based on pre-meal glucose readings 2

Follow-up Recommendations

• Monitor blood glucose 4 times daily (before meals and at bedtime) for the first week after transition 1
• Adjust Lantus dose if fasting blood glucose is consistently above target for 2-3 days 2
• Consider consultation with endocrinology if glycemic targets are not achieved within 2-4 weeks 1