Concentrated Insulins: The Basics

The Food and Drug Administration (FDA) recently approved insulin glargine U-300 (Toujeo®), and insulin lispro U-200 (Humalog® U-200).

These insulins were previously only available at concentrations of 100 units per milliliter, and like their U-100 counterparts, are indicated for types 1 and 2 diabetes. Most patients need 0.2 to 1 unit/kg/day but some type 2 patients may need as much as 3 units/kg/day.

Many clinicians recommend a limit of 50 units per injection to ensure predictable absorption, but evidence supporting this recommendation is scant. U-500 insulin has more predictable day-to-day absorption at high doses because its volume is 80% less lower than other insulins. These new concentrated insulin products are believed to provide this benefit as well.

Both commercially available insulin lispro products (U-100 and U-200) are bioequivalent, and patients switching between the two do not need to adjust their doses.

U-300 insulin glargine has a more consistent release profile than the U-100 strength and a slightly slower onset of action (6 hours vs. 3-4 hours). U-300 insulin glargine seems to cause less nocturnal hypoglycemia and severe hypoglycemia (hypoglycemia requiring glucagon or glucose administration by a caregiver)” than its less concentrated counterpart. Both insulin glargine products also have similar bioavailability, so no dose adjustments are needed to switch patients.

Patients switching from NPH to either insulin glargine product should reduce their daily dose by 20%.

The prices of the new and established insulins are comparable per insulin unit but the concentrated insulin pen packages contain slightly less insulin in total. Toujeo® branded U-300 insulin glargine has 1350 units per package (10% less than Lantus® branded U-100) and Humalog® U-200 insulin lispro has 1200 units per package (20% less than Humalog® U-100). Both concentrated insulin pens require the patient to dial the dose by unit instead of milliliter; this helps prevent dosing errors.

The new concentrated insulins can temper absorption variability in patients requiring high doses.

Patients do not need to make a dose change when switching between strengths but providers should ensure the patient is aware of the volume change.