Insulin is an important hormone made by the
pancreas. It is also a medication (actually, a group of medications) used to treat
diabetes. There are many different types of these medications, which vary in how quickly they start to work and how long they last in the body.
Currently, all of the insulin medications sold in the United States are made by one of the following three manufacturers:
- Eli Lilly and Company
- Novo Nordisk
- sanofi-aventis.
Insulin is a hormone that is naturally produced by the pancreas.
This hormone is important for several functions, such as controlling blood sugar. It helps the cells of your body remove glucose ("sugar") from your bloodstream. This sugar fuels your body's cells, giving them the energy they need to work properly. You may need to take this hormone as a medication if your pancreas has trouble making enough of it, which is the case in people with
type 1 diabetes and in some people who have
type 2 diabetes.
Even though it is made in a laboratory, standard, "regular" insulin is identical to the hormone produced by the human body. Over the years, scientists have developed ways to slightly change the insulin molecule to change the way it works in the human body. Some forms are designed to start working quickly and to last only a short while. These are known as rapid-acting insulins and are used to control increases in blood sugar levels after meals. Other types are designed to provide a steady, slow, background rate of the hormone that lasts for a long period of time. These are known as long-acting insulins. There are also short-acting and intermediate-acting versions.
Some general considerations for when and how to take the medication include the following:
- Currently, insulin must be taken by injection just under the skin (subcutaneously), using pumps, or in an IV (only in certain situations). At one point, inhaled insulin (Exubera®) was available, but it has been taken off the market due to low sales.
- Your healthcare provider should show you exactly how to inject it. It can be injected into the skin and fat layer of the abdomen (stomach), upper arm, or thigh.
- Some insulins come in a suspension that settles with time. These products must be shaken or rolled to "re-suspend" the insulin. Make sure to follow the instructions for your particular product.
- Some insulins can be mixed with other insulins in the same syringe, while others cannot. Do not mix them unless you are certain that you can safely do so.
- For this diabetes drug to work properly, it must be taken as directed. Make sure to monitor your blood sugar levels as your healthcare provider recommends. Even though some forms of insulin are available without a prescription, you should not use any insulin medication without a healthcare provider's approval and supervision.
The dosage that your healthcare provider recommends will vary, depending on a number of factors, including:
- The carbohydrate content of your meals
- Your blood sugar goals (which can vary from person to person)
- Your blood sugar levels
- Other medications you are taking, including other diabetes medications
- Other medical conditions you may have.
As is always the case, do not adjust your dose unless your healthcare provider specifically instructs you to do so.
As with any medicine, insulin can cause side effects. Possible side effects of this
diabetes medication (as well as all other forms of insulin) include, but are not limited to:
- A skin reaction at the injection site
- Low blood sugar levels (hypoglycemia)
- Thickening or pitting of the skin at the injection site
- Weight gain (see Insulin and Weight Gain).
(Click Insulin Side Effects to learn more, including potentially serious side effects you should report immediately to your healthcare provider.)
What Should I Tell My Healthcare Provider Before Taking Insulin?
Talk with your healthcare provider prior to taking this medication if you have:
- Liver disease, such as liver failure, cirrhosis, or hepatitis
- Kidney disease, such as kidney failure (renal failure)
- Any allergies, including allergies to foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
What If I Take an Overdose?
People who take too much of any type of insulin may experience symptoms such as:
- Low blood sugar levels (hypoglycemia)
- Fainting
- Shakiness
- A fast heartbeat (tachycardia)
- Confusion
- Sweating
- Seizures
- Coma
- Loss of life.
If you happen to take too much, seek immediate medical attention.
In general, insulin should be stored in the refrigerator (not freezer) until you start using it. After that, the recommended storage conditions depend on what type of the medication you use. Insulin pens and cartridges should not be stored in the refrigerator once you start using them. Vials in use are best kept in the refrigerator, but can usually be stored at room temperature for a certain period of time (which varies depending on the type of insulin).
Almost all insulins available today come in U-100 strength (100 units of insulin per mL). There is also a very concentrated form of
regular insulin known as U-500 insulin (500 units of insulin per mL).
Generic Insulin Availability
At this time, the medication is not available in generic form
(see Generic Insulin).
