Diabetes Type I...Insulin Therapy (cont.)

The Present

At present, injectable insulin is commonly available. Insulin now comes in a variety of preparations that differ in time of onset and length of action. Because of these differences, combinations of insulin are often used to allow for a more tailored regimen of blood sugar control. The table below lists the most common types of insulin currently in use in the United States, and their specific properties.

Name of Insulin Onset of Action Peak Effect after Injection
Humalog/Novolog/Very Short Acting 5-15 minutes 30-60 minutes
Regular/Short Acting 30 minutes 2-5 hours
NPH/Intermediate Acting 1-2.5 hours 8-14 hours
Lente/Intermediate Acting 1-2.5 hours 8-12 hours
Ultra Lente/Long Acting 4-6 hours 10-18 hours
Combinations - 70/30, 50/50, 75/25 30 minutes 7-12 hours

For example, a patient may take an injection of Lente in the morning and evening to provide a baseline of insulin throughout a 24-hour period. In addition, the same patient may take an injection of Humalog just before meals to cover the increase in carbohydrate load after eating.

Not only is the variety of insulin preparations available growing, so are the methods for administering insulin. In the past, insulin was available only in an injectable form. This involved carrying syringes (which a few decades age were made of glass and required sterilization), needles, vials of insulin, and alcohol swabs. Needless to say, patients often found it difficult to take multiple shots a day, and as a result, good blood sugar control was often compromised. Many pharmaceutical companies are now offering discreet and convenient methods of insulin delivery. Novo Nordisk and Lily and Aventis have an insulin pen delivery system. This system is similar to an ink cartridge in a fountain pen. A small pen-sized device holds an insulin cartridge (usually containing 300 units). Cartridges are available in the most widely used insulin formulations, such as those listed in the table above. The amount of insulin to be injected is dialed in by turning the bottom of the pen until the required number of units is seen in the dose-viewing window. The tip of the pen consists of a needle that is replaced with each injection. A release mechanism allows the needle to penetrate just under the skin and deliver the required amount of insulin. The cartridges and needles are disposed of when finished, and new ones are simply inserted. These insulin delivery devices are discreet and less cumbersome than traditional methods.