Untitled Document

Types of Insulin

There are more than 20 types of insulin sold in the US today.

Insulin is classified by:

it's source – what it’s made from
it’s onset – how soon it starts working;
its peak time – when it exerts the most effect on blood glucose; and
it’s duration – how long it lasts in the body.

As individuals differs in their response to insulin, the onset, peak time, and duration of various insulin preparations are given as ranges. Insulin available in the U.S. is obtained either directly from pork pancreas or from chemical modification of pork insulin. It is also made chemically identical to human insulin by recombinant DNA technology. Human insulin manufactured using recombinant DNA technology is replacing pork insulin. Beef insulin differs from human insulin at 3 amino acid sites and pork insulin differs at one site. As a result, beef insulin causes more allergic reactions than pork insulin, and is not available in the U.S.

Different types and species of insulin have different pharmacological properties. Human insulin is recommended for pregnant women, women considering pregnancy, people with allergies or immune resistance to animal-derived insulins, and people beginning insulin therapy. Changing insulin species may affect blood glucose control and should only be done under the supervision of a health professional with expertise in diabetes management. If a patient is admitted to the hospital, the type of insulin he or she has been using should not be changed indiscriminately. In all instances of insulin use, dosages must be individualized and balanced with medical nutrition therapy and exercise.

Instant Feedback:

The indications for using pork and human insulin are essentially the same.

The synthetic human insulins lispro and aspart are the fastest acting insulins available. Lispro and aspart reach the bloodstream 15 minutes or less after injection, have a peak action between thirty and ninety minutes, and a maximum duration of action between 4 and 6 hours. They should be injected no more than 15 minutes before a meal, and can also be injected immediately after eating because of their rapid absorption and peak timing profiles. Because lispro and aspart act so quickly, it’s important that a person using these types of rapid-acting insulins begin to eat his or her meal immediately.

Short acting or regular insulin usually reaches the blood within 30 minutes after injection, peaks in 2 to 4 hours and stays in the bloodstream for 6 to 8 hours. Intermediate acting (NPH and lente) insulins reach the bloodstream 2 to 4 hours after injection. They peak within 6 to 8 hours and stay in the bloodstream for 16 to 20 hours. Long acting (ultralente) insulin takes 6 to 8 hours to reach the bloodstream. It has no peak or a very small peak 10 to 16 hours after injection. It stays in the bloodstream 24 hours or longer.

The human insulin ultralente and the synthetic human insulin glargine are long acting insulins. Glargine is given once a day at bedtime. With a timing profile of about 24 hours and no pronounced peak effect, glargine provides basal insulin coverage over an entire day and night.

Instant Feedback:

Lispro and aspart insulins can be injected immediately after a meal.

Different companies have adopted different names for the same short, intermediate, or long action types of insulin or their mixtures. Combinations of insulins, such as Humulin ® 70/30 or Novolin ® 70/30 are also available. This chart shows some common trade names for various insulin preparations.

Rapid acting insulins	Human insulin analogues - Humalog ® lispro and Novolog ® aspart
Short acting ("Regular") insulins	Human sources - Humulin ® R regular, Novolin ® R regular, and Velosulin ® BR regular Pork sources - Iletin II ® regular and Purified Pork regular
Intermediate acting insulins	Human sources - Humulin ® L (Lente), Humulin ® N (NPH), Novolin ® L (Lente), and Novolin ® (NPH) Pork sources - Iletin ® II, Iletin II ® NPH, Purified Pork Lente and Purified NPH
Long-acting insulins	Human source – Humulin ® U (Ultralente) Human insulin analogue – Lantus ® (insulin glargine)
Source: Pharmacologic therapies. (2001). Diabetes Management Therapies: A Core Curriculum for Diabetes Education (4th Ed.) American Association of Diabetes Educators, p. 95.

Because of it’s short and predictable peak action, regular insulin is the insulin product routinely used for intravenous administration.

Insulin concentrations currently available in the U.S. are U-100 and U-500, indicating 100 units or 500 units per milliliter. U-500 is only used in rare cases of insulin resistance when the patient requires extremely large doses. Travelers should be aware that insulin is available in a U-40 strength outside the U.S. To avoid dosing errors, syringes that match the concentration of U-40 insulin must be used.

Instant Feedback:

U-40 is the insulin preparation most commonly used in the U.S.