Different diabetic patients require different types of insulin according to their specific situation and type of diabetes. There are three types of insulin: rapid acting insulin, intermediate acting insulin, and long acting insulin. Dr. Sonal Chaudhry, an adult Endocrinologist, explains what the differences between each of these are and which type of insulin you should expect to require.
Rapid acting insulins are absorbed quickly, they peak anywhere from 30-60 minutes, and last between 2-4 hours. They are used to cover glucose excursions at meal time and during snacks.
Intermediate acting insulins are absorbed slower than the rapid acting insulins. They also take longer to peak and have a longer duration of action. They're used primarily overnight, fasting, and in between meals.
Long acting insulins are absorbed more slowly than intermediate acting insulin, they take longer to peak, and they have the longest duration of action (typically over a 24 hour period of time). These are also used to control blood sugars overnight and in between meals.
How do you know which type of insulin you might need? It depends on the type of diabetes the patient has.
Some patients require two different types of insulin to control their blood sugar during the day and at night. Type 1 diabetics require both rapid and long acting insulin. They require the rapid acting insulin to cover their glucose excursions with meals and snacks and they require long acting insulin to keep their blood sugar under control between meals as well as overnight.
Type 2 diabetics produce some of their own insulin naturally, so they don't necessarily always need both long acting and rapid acting insulin. In the beginning you can sometimes get by with just prescribing a dose of long acting insulin to control their fasting blood sugars and they can take other medicines to control their post meal excursions.
If a patient is not meeting their glucose targets, the next step is intensification of therapy. At that point, they'll add mealtime insulin in addition to their long acting insulin.