Insulin Therapy
All people with Type 1—and some with Type 2—rely on an insulin therapy in order to control their diabetes.
There are a variety of insulin preparations that perform in different ways, and may be needed at different times of the day. Your physician will help you work out a plan for which insulins to use and when.
A very simple pattern might look like this: At bedtime, a shot is injected; this is called the “basal” insulin. This would be a long-acting, time-released insulin that will last throughout the night to control the glucose produced by the liver. (This is also called “background” insulin.) But a different insulin may be needed to cover the glucose produced as you digest a meal. You might inject a rapid-acting insulin, which would work to cover the rise in glucose that results when you digest the carbohydrates in the food. That dose may have to vary, depending on how much carb has been eaten and how high or low the glucose level may be at the time of injection.
This list describes the major types of insulin, and gives a general overview on how they work, how they are usually used, and any special considerations to keep in mind. Some examples are also listed. Look to your healthcare provider for more complete information on any medication you may be prescribed, as well as for specific instructions on how you should be using it in your diabetes management.
Long-acting and intermediate-acting insulins
These are also called background insulins. They include:
- Lente and NPH insulin (Humulin N®, Novolin N®). Usually given once or twice daily, at least 8 to 12 hours apart.
- Insulin glargine (Lantus®). Usually given once daily at bedtime; some people prefer it in the morning.
- These insulins are usually given in the same dose every day once the correct dose is determined.
Short-acting (or rapid-acting) insulins
These are used to cover the carbohydrates in a meal; they are also given to help bring down high blood glucose. They include:
- Regular insulin (Humulin R®, Novolin R®). Usually given 30 minutes before the meal.
- Aspart (Humalog®) and lispro (Novolog®). Can be given just before, during, or just after the meal. These two are very fast acting and may be able to allow for more flexibility in timing of meals.
Pre-mixed insulins
These are combinations of long-acting and rapid-acting.Two of the major types are called 70/30 and 75/25 (the numbers are the percentages of each type, with the long-acting insulin being the first number).
These pre-mixed insulins may be helpful for people who are not comfortable managing a more complicated insulin routine. However, they do require a set routine of established meal times with predictable amounts of food.
Insulin delivery systems
Insulin is injected just under the skin in a fatty area, such as the stomach, thigh, or back of the arm. People tend to rotate their injections among different areas.
The traditional, and perhaps most common, way to administer insulin is with a syringe. However, other technologies have been developed and are becoming increasingly popular. These include insulin pens and insulin pumps.
The insulin pen looks much like an old-fashioned fountain pen. It holds a small cartridge of insulin, with a needle in the tip. The cartridge generally holds 150-200 units of insulin, but for sanitary reasons the needle is replaced with each injection. Insulin pens are easy to carry, and they allow the insulin user to take an injection while being very discrete—for example, in a restaurant or at the office.
An insulin pump is the size of a small beeper and is worn on the belt or hidden within in clothing. The pump holds a reservoir of 150-300 units of insulin and literally “pumps” a flow of insulin through a thin tube to an insertion set just under the skin in the stomach area. Pumps have many advantages, especially for people who would otherwise take multiple injections each day. However, they may not be a good fit for every potential user. Managing with a pump takes some extra work, and usually makes sense only for those who are very comfortable with the challenges of maintaining good control.
