Insulin nomenclature   (August 21, 2007)

Insulin nomenclature is clearly confusing. Among other reasons:

• The same product may have several different names; the names may be different in the U.S. compared to other countries; the same product may be made by several manufacturers and given differing names.
• The product may be from different sources (previously all insulin came from animal pancreases: beef, pork, or mixed beef/pork; but now-a-days, insulins usually are semisynthetic human).
• Insulins are classified by duration of action, as being rapid, intermediate, and prolonged.
• Several manufacturers may also mix two insulin products into the same vial, producing mixtures of 70% one and 30% another, or 50/50. To make it worse, what the US calls 70/30 would be called 30/70 in Europe! And in the US, 70/30, 75/25, and 50/50 are the usual mixtures, but in Europe there will be others such as 80/20 (oops, 20/80).

Some of the "big players" in the insulin arena are described below. I give the U.S. brand name first, then common name, then manufacturer. All of these are only available as branded products, and all are semisynthetic:

Prolonged duration of action:

• Lantus (insulin glargine) sanofi-aventis
• Levemir (insulin detemir) Novo-Nordisk

Rapid-acting insulins:

• Humalog (insulin lispro) Eli Lilly
• Novolog (insulin aspart) Novo-Nordisk
• Apidra (insulin glulisine) sanofi-aventis
• Exubera (inhaled insulin) Pfizer

Mixtures:

• Humalog Mix75/25 (Insulin Lispro Protamine Suspension/Insulin Lispro Injection) Eli Lilly
• NovoLog Mix 70/30 (Insulin Aspart Protamine/Insulin Aspart) Novo-Nordisk

The following insulins are older products, and have been made by several companies, and are falling out of favor by the medical profession as newer products (above) are perceived as being "better," or at least easier to manufacture. These have frequently been animal-source (beef, beef-pork, or pork).

Rapid-acting:

• Regular
• Semilente (no longer used)

Intermediate duration of action:

• NPH (isophane)
• Lente (rarely used)

Prolonged duration of action:

• Ultralente (rarely used)
• PZI (no longer used)

So what's the impact of all this for you? If you're an endocrinologist, or pharmacy student or medical student, you'll have to keep most of this in mind. If you're a patient on one or more of these, and doing fine, don't worry. But if you're a patient and having some problem with your insulin, you might want to really wow your physician or diabetes nurse educator, and suggest switching to another type of insulin - and propose an alternate to him or her.