What is the recommended conversion to 70/30 (Novolin 70/30, NPH/Regular insulin) insulin twice daily (bid) dosing for a patient on Lantus (insulin glargine) 12 units at bedtime (HS) and Humalog (insulin lispro) 5 units three times a day (tid) before meals (ac)?

From the Guidelines

For a patient transitioning from Lantus 12 units at bedtime and Humalog 5 units three times daily before meals to Novolin 70/30 twice daily, I recommend starting with a total daily dose of 27 units of 70/30 insulin, divided as 18 units in the morning and 9 units in the evening. This approach is based on the principle of maintaining the total daily insulin dose while adjusting for the different insulin types and their action profiles, as suggested by recent guidelines on pharmacologic approaches to glycemic treatment 1. The total daily dose of 27 units is derived from adding the Lantus and Humalog doses together (12 units + 15 units = 27 units), and then dividing this total into morning and evening doses, with the morning dose being larger (2/3 of the total dose) to cover both breakfast and lunch, and the evening dose (1/3 of the total dose) covering dinner and overnight needs. Key considerations include:

• Monitoring blood glucose levels closely, especially before meals and at bedtime, due to individual variability in response to insulin regimen changes.
• The composition of 70/30 insulin, which includes 70% NPH (intermediate-acting) and 30% regular insulin (short-acting), providing both basal and prandial coverage.
• Potential need for dosage adjustments based on observed blood glucose patterns, with morning doses primarily affecting daytime glucose levels and evening doses affecting overnight glucose levels. Guidelines from 2025 standards of care in diabetes suggest considering self-mixed or premixed insulin plans for simplification and to decrease the number of injections required 1. It's crucial to tailor the insulin regimen to the individual's needs, preferences, and response to therapy, ensuring optimal glycemic control while minimizing the risk of hypoglycemia and other adverse effects.

From the Research

Conversion to 70/30 Insulin Bid Dosing

To convert a patient from Lantus 12 units at bedtime and Humalog 5 units three times a day to 70/30 insulin twice daily, consider the following steps:

• The total daily dose of Humalog is 15 units (5 units x 3 times a day).
• The total daily dose of Lantus is 12 units.
• The 70/30 insulin contains 70% NPH (intermediate-acting) and 30% regular insulin (short-acting).

Calculating the 70/30 Insulin Dose

• The NPH component of 70/30 insulin can be considered equivalent to Lantus in terms of basal coverage, but with a shorter duration of action. Therefore, the 12 units of Lantus can be converted to NPH, considering its shorter duration of action, the dose might need to be split into two injections.
• The regular insulin component of 70/30 insulin can be considered equivalent to Humalog in terms of mealtime coverage. However, since 70/30 insulin contains 30% regular insulin, the total daily dose of 70/30 insulin will need to be calculated based on the patient's total daily insulin needs.

Recommended Conversion

• A common approach is to start with a total daily dose of 70/30 insulin that is equivalent to the patient's current total daily insulin dose (Lantus + Humalog). In this case, the total daily dose would be 27 units (12 units Lantus + 15 units Humalog).
• Since the patient is taking 70/30 insulin twice daily, the total daily dose can be split into two injections, with 13.5 units in the morning and 13.5 units in the evening.
• However, this is a general guideline, and the actual dose may need to be adjusted based on the patient's individual needs and response to the new insulin regimen, as seen in studies such as 2, 3, 4, 5, 6.

Key Considerations

• The patient's blood glucose levels should be closely monitored after converting to 70/30 insulin, and the dose adjusted as needed to achieve optimal glycemic control.
• The patient should be educated on the proper administration of 70/30 insulin, including the importance of injecting the insulin at the same time every day and adjusting the dose based on blood glucose levels.
• Studies have shown that insulin glargine, a long-acting insulin analog, can be administered once daily at bedtime, providing 24-hour basal insulin coverage 6. However, the conversion to 70/30 insulin bid dosing requires careful consideration of the patient's individual needs and response to the new insulin regimen.