Is 70/30 (seventy/thirty) insulin considered a long-acting insulin?

70/30 Insulin Is Not a Long-Acting Insulin

No, 70/30 insulin is not a long-acting insulin but rather a premixed insulin formulation containing 70% intermediate-acting NPH insulin and 30% short-acting regular insulin. 1

Understanding 70/30 Insulin Composition and Classification

70/30 insulin is a premixed formulation that combines:

• 70% NPH insulin (intermediate-acting)
• 30% Regular insulin (short-acting)

This combination provides both:

1. Initial coverage of mealtime glucose needs (from the regular insulin component)
2. Extended coverage for several hours after meals (from the NPH component)

Unlike true long-acting insulins such as glargine, detemir, or degludec that provide relatively peakless coverage for 24+ hours, 70/30 insulin has a distinct peak action profile 1, 2.

Pharmacokinetic Differences Between Insulin Types

Insulin Type	Classification	Onset	Peak	Duration	Examples
70/30 Premixed	Combination	30-60 min	2-12 hours	16-24 hours	Humulin 70/30, Novolin 70/30
Long-Acting	Basal	1-2 hours	Minimal peak	24+ hours	Glargine, Detemir, Degludec

According to the American Diabetes Association guidelines, insulin glargine is considered a true long-acting basal insulin analog with an onset of 1-2 hours, a relatively peakless action profile, and a duration of 24+ hours 1.

Clinical Implications of 70/30 vs. Long-Acting Insulin

The distinction between 70/30 and long-acting insulin has important clinical implications:

• Administration timing: 70/30 insulin must be administered 30-60 minutes before meals due to its regular insulin component 1
• Dosing frequency: 70/30 insulin typically requires twice-daily dosing, while long-acting insulins often allow once-daily administration 1, 3
• Meal pattern requirements: 70/30 insulin works best for patients with consistent meal patterns and timing 1
• Hypoglycemia risk: Premixed insulins like 70/30 may carry a higher risk of hypoglycemia compared to true long-acting insulins due to their peak action 2, 4

Common Pitfalls When Using 70/30 Insulin

1. Misclassification: Incorrectly considering 70/30 as a long-acting insulin can lead to inappropriate dosing and timing
2. Inappropriate patient selection: Using 70/30 in patients with irregular meal patterns increases hypoglycemia risk 1
3. Inpatient use concerns: Premixed insulin therapy is not recommended for inpatient use due to high rates of iatrogenic hypoglycemia 1
4. Inflexible dosing: The fixed ratio limits dose adjustment flexibility compared to separate basal-bolus components

When to Consider 70/30 vs. Long-Acting Insulin

70/30 insulin may be appropriate for:

• Older adults with consistent meal patterns 1
• Patients who need simplified regimens 1, 5
• Situations where twice-daily dosing provides better glycemic control than once-daily basal insulin 3

True long-acting insulins are preferred for:

• Patients requiring flexible meal timing
• Those needing basal-only coverage
• Situations requiring minimal peak effect
• Patients at higher risk for hypoglycemia 2, 4

For patients transitioning from premixed insulin like 70/30, the American Diabetes Association recommends converting to a simplified regimen with 70% of the total daily dose as basal insulin (long-acting) administered in the morning 1.