Is it normal to use Humalog (insulin lispro) 70/30 and Humalog Mix 75/25 (insulin lispro protamine and insulin lispro) together?

Using Humalog 70/30 and Humalog 75/25 Together in Diabetes Management

Using both Humalog 70/30 and Humalog 75/25 together in the same treatment regimen is not recommended and is not considered standard practice in diabetes management. 1

Understanding Premixed Insulin Formulations

• Humalog Mix75/25 (75% insulin lispro protamine/25% insulin lispro) and Humalog 70/30 (70% insulin lispro protamine/30% insulin lispro) are both premixed insulin formulations designed for twice-daily dosing, typically before breakfast and dinner 1
• These premixed insulins have different ratios of intermediate-acting to rapid-acting insulin components, which affects their pharmacodynamic profiles 1
• Premixed insulins are designed to provide both basal and prandial insulin coverage in a single injection 1

Recommended Insulin Regimens

Standard Approaches to Insulin Therapy

• When basal insulin alone is insufficient to achieve glycemic targets, guidelines recommend several options:

  • Adding a GLP-1 receptor agonist 1
  • Adding a single injection of rapid-acting insulin before the largest meal 1
  • Switching to twice-daily premixed insulin (such as 70/30 or 75/25) 1

• For patients requiring premixed insulin, guidelines recommend using a single formulation consistently:

  • Either 70/30 aspart mix or 75/25 lispro mix administered twice daily, typically before breakfast and dinner 1
  • If glycemic targets are still not met with twice-daily dosing, consider advancing to thrice-daily premixed insulin 1

Intensification of Insulin Therapy

• If twice-daily premixed insulin is insufficient, guidelines recommend:
  • Increasing to thrice-daily premixed insulin using the same formulation 1
  • Alternatively, switching to a basal-bolus regimen 1
  • In either case, using a single consistent formulation is the standard approach 1

Why Using Both Formulations Together Is Problematic

• Using two different premixed insulin formulations (70/30 and 75/25) simultaneously:

  • Creates unnecessary complexity in the regimen 1
  • Increases risk of dosing errors 1
  • Makes it difficult to interpret blood glucose patterns and adjust doses appropriately 1
  • Has not been studied in clinical trials as a combination approach 1

• Research studies have compared the efficacy of Humalog Mix75/25 versus human insulin 70/30, but always as alternative treatments, not used together 2, 3

Clinical Considerations

• For older adults or those with complex regimens, guidelines specifically recommend simplification of insulin regimens to reduce the risk of hypoglycemia 1
• Using multiple insulin formulations increases regimen complexity and may lead to confusion and medication errors 1
• Studies show that premixed insulin formulations can be effective when used consistently as part of a structured regimen 2, 4, 3
• If current therapy is not achieving glycemic targets, guidelines recommend changing to a different regimen entirely rather than adding another insulin formulation 1

Alternative Approaches

• If twice-daily premixed insulin is insufficient:

  • Consider thrice-daily dosing of a single premixed formulation 1, 5
  • Consider switching to basal-bolus therapy with separate basal and prandial insulins 1
  • Evaluate for medication adherence issues, dietary factors, or other causes of suboptimal control 1

• For patients requiring simplified regimens:

  • Choose a single premixed insulin formulation that best matches their glucose pattern 1
  • Consider once-daily basal insulin if appropriate for the patient's needs 1

In conclusion, using both Humalog 70/30 and 75/25 simultaneously is not standard practice and could lead to confusion, dosing errors, and difficulty in interpreting glucose patterns. The recommended approach is to select a single premixed insulin formulation and adjust the dosing schedule as needed to achieve glycemic targets.