Insulin (parenteral route)

Proper Use

Make sure you have the type (beef and pork, pork, or human) and the strength of insulin that your doctor ordered for you. You may find that keeping an insulin label with you is helpful when buying insulin supplies.

The concentration (strength) of insulin is measured in USP Insulin Units and USP Insulin Human Units and is usually expressed in terms such as U-100 insulin. Insulin doses are measured and injected with specially marked insulin syringes. The appropriate syringe is chosen based on your insulin dose to make measuring the dose easy to read. This helps you measure your dose accurately. These syringes come in three sizes: 3/10 cubic centimeters (cc) measuring up to 30 USP Units of insulin, ½ cc measuring up to 50 USP Units of insulin, and 1 cc measuring up to 100 USP Units of insulin.

It is important to follow any instructions from your doctor about the careful selection and rotation of injection sites on your body.

There are several important steps that will help you successfully prepare your insulin injection. To draw the insulin up into the syringe correctly, you need to follow these steps:

• Wash your hands with soap and water.
• If your insulin contains zinc or isophane (normally cloudy), be sure that it is completely mixed. Mix the insulin by slowly rolling the bottle between your hands or gently tipping the bottle over a few times.
• Never shake the bottle vigorously (hard).
• Do not use the insulin if it looks lumpy or grainy, seems unusually thick, sticks to the bottle, or seems to be even a little discolored. Do not use the insulin if it contains crystals or if the bottle looks frosted. Regular insulin (short-acting) should be used only if it is clear and colorless.
• Remove the colored protective cap on the bottle. Do not remove the rubber stopper.
• Wipe the top of the bottle with an alcohol swab.
• Remove the needle cover from the insulin syringe.

How to prepare your insulin dose if you are using one type of insulin:

• Draw air into the syringe by pulling back on the plunger. The amount of air should be equal to your insulin dose.
• Gently push the needle through the top of the rubber stopper with the bottle standing upright.
• Push plunger in all the way to inject air into the bottle.
• Turn the bottle with syringe upside down in one hand. Be sure the tip of the needle is covered by the insulin. With your other hand, draw the plunger back slowly to draw the correct dose of insulin into the syringe.
• Check your dose. Hold the syringe with the scale at eye level to see that the proper dose is withdrawn and to check for air bubbles. Tap gently on the measuring scale of the syringe to move any bubbles to the top of the syringe near the needle. Then, push the insulin slowly back into the bottle and draw up your dose again.
• If your dose measures too low in the syringe, withdraw more solution from the bottle. If there is too much insulin in the syringe, put some back into the bottle. Then check your dose again.
• Remove the needle from the bottle and re-cover the needle.

How to prepare your insulin dose if you are using two types of insulin:

• When you mix regular insulin with another type of insulin, always draw the regular insulin into the syringe first. When you mix two types of insulins other than regular insulin, it does not matter in what order you draw them into the syringe.
• After you decide on a certain order for drawing up your insulin, you should use the same order each time.
• Some mixtures of insulins have to be injected immediately. Others may be stable for longer periods of time, which means that you can wait before you inject the mixture. Check with your health care professional to find out which type you have.
• Draw air into the syringe by pulling back on the plunger. The amount of air in the syringe should be equal to the part of the dose that you will be taking from the first bottle. Inject the air into the first bottle. Do not draw the insulin yet. Next, draw into the syringe an amount of air equal to the part of the dose that you will be taking from the second bottle. Inject the air into the second bottle.
• Return to the first bottle of the combination. With the plunger at zero, draw the first insulin dose of the combination (usually regular insulin) into the syringe.
• Check your dose. Hold the syringe with the scale at eye level to help you see that the proper dose is withdrawn and to check for air bubbles. Tap gently on the measuring scale of the syringe to move any bubbles to the top of the syringe near the needle.
• At this point, if the first part of the dose measures too low in the syringe, you can withdraw more solution from the bottle. If there is too much insulin in your syringe, put some back into the bottle. Then check your dose again.
• Then, without moving the plunger, insert the needle into the second bottle of insulin and withdraw the dose. Sometimes withdrawing a little bit more insulin from the second bottle than needed will help you correct the second dose more easily when you remove the air bubbles.
• Again, check that the proper dose is withdrawn. The syringe will now contain two types of insulin. It is important not to squirt any extra solution from the syringe back into the bottle. Doing so might change the insulin in the bottle. Throw away any extra insulin in the syringe.
• If you are not sure that you have done this correctly, throw away the dose into the sink and begin the steps again. Do not place any of the solutions back into either bottle. You can use the same syringe to begin the procedure again.
• If you prepared your mixture ahead of time, gently turn the filled syringe back and forth to remix the insulins before you inject them. Do not shake the syringe.

How to inject your insulin dose:

• After you have prepared your syringe and chosen the area of your body to inject, you are ready to inject the insulin into the fatty skin.
  • Clean the area where the injection is to be given with an alcohol swab or with soap and water. Let the area dry.
  • Pinch up a large area of skin and hold it firmly. With your other hand, hold the syringe like a pencil. Push the needle straight into the pinched-up skin at a 90-degree angle for an adult or at a 45-degree angle for a child. Be sure the needle is all the way in. It is not necessary to draw back on the syringe each time to check for blood (also called routine aspiration).
  • Push the plunger all the way down, using less than 5 seconds to inject the dose. Let go of the skin. Hold an alcohol swab near the needle and pull the needle straight out of the skin.
  • Press the swab against the injection area for several seconds. Do not rub.
  • If you are either thin or greatly overweight, you may be given special instructions for giving yourself insulin injections.

How to use special injection devices:

• It is important to follow the information that comes with your insulin and with the device you use for injecting your insulin. This will ensure proper use and proper insulin dosing. If you need more information about this, ask your health care professional.

For patients using an automatic injector (with a disposable syringe):

• After the dose is drawn, the disposable syringe is placed inside the automatic injector. Pressing a button on the device quickly plunges the needle into the skin, releasing the insulin dose.

For patients using a continuous subcutaneous infusion insulin pump:

• Buffered regular human insulin, when available, is the recommended insulin for insulin pumps. Otherwise non-buffered regular insulin can be used.
• The pump consists of a tube, with a needle on the end of it that is taped to the abdomen, and a computerized device that is worn at the waist. Insulin is received continuously from the pump. A button is pressed at mealtime to release an extra insulin dose.
• It is important to follow the pump manufacturer's directions on how to load the syringe and/or pump reservoir. If you do not load the syringe and/or pump properly, you may not get the correct insulin dose.
• Check the infusion tubing and infusion-site dressing as often as your health care professional recommends to make sure the pump is working properly.

For patients using disposable syringes:

• Manufacturers of disposable syringes recommend that they be used only once, because the sterility of a reused syringe cannot be guaranteed. However, some patients prefer to reuse a syringe until its needle becomes dull. Most insulins have chemicals added that keep them from growing the bacteria that are usually found on the skin. However, the syringe should be thrown away when the needle becomes dull, has been bent, or has come into contact with any surface other than the cleaned and swabbed area of skin. If you plan to reuse a syringe, the needle must be recapped after each use. Check with your health care professional to find out the best way to reuse syringes.

For patients using an insulin pen device (cartridge and disposable needles):

• Change the dose by rotating the head of the pen. Put the pen next to your skin and press the plunger to inject the medicine. Some pen devices can only inject certain doses of insulin with each injection. Injection amounts can be different for different pen devices. To receive the right dose, you might have to count the number of times you press the plunger. Also, these devices use special cartridges of isophane insulin (NPH), regular insulin (R), or a mixture of these two types.

For patients using nondisposable syringes (glass syringe and metal needle):

• These types of syringes and needles may be used repeatedly if they are sterilized after each use. You should get an instruction sheet that tells you how to do this. If you need more information about this, ask your health care professional.

For patients using a spray injector (device without needles):

• The dose is measured by rotating part of the device. Insulin is drawn up into the spray device from an insulin bottle. Pressing a button forcefully sprays the insulin dose into the skin. This involves a wider area of skin than an injection would.

Laws in some states require that used insulin syringes and needles be destroyed. Be careful when you recap, bend, or break a needle, because these actions increase the chances of a needle-stick injury. It is best to put used syringes and needles in a disposable container that is puncture-resistant (such as an empty plastic liquid laundry detergent or bleach bottle) or to use a needle-clipping device. The chance of a syringe being reused by someone else is smaller if the plunger is taken out of the barrel and broken in half when you dispose of a syringe.

Use this medicine only as directed. Do not use more or less insulin than recommended by your doctor. To do so may increase the chance of serious side effects.

Your doctor will give you instructions about diet, exercise, how to test your blood sugar levels, and how to adjust your dose when you are sick.

• Diet—The daily number of calories in the meal plan should be adjusted by your doctor or a registered dietitian to help you reach and maintain a healthy body weight. In addition, regular meals and snacks are arranged to meet the energy needs of your body at different times of the day. It is very important that you carefully follow your meal plan.
• Exercise—Ask your doctor what kind of exercise to do, the best time to do it, and how much you should do each day.
• Blood tests—This is the best way to tell whether your diabetes is being controlled properly. Blood sugar testing helps you and your health care team adjust your insulin dose, meal plan, and exercise schedule.
• Changes in dose—Your doctor may change the first dose of the day. A change in the first dose of the day might change your blood sugar later in the day or change the amount of insulin you should use in other doses later that day. That is why your doctor should know any time your dose changes, even temporarily, unless you have been told otherwise.
• On sick days—When you become sick with a cold, fever, or the flu, you need to take your usual insulin dose, even if you feel too ill to eat. This is especially true if you have nausea, vomiting, or diarrhea. Infection usually increases your need for insulin. Call your doctor for specific instructions. Continue taking your insulin and try to stay on your regular meal plan. However, if you have trouble eating solid food, drink fruit juices, nondiet soft drinks, or clear soups, or eat small amounts of bland foods. A dietitian or your doctor can give you a list of foods and the amounts to use for sick days. Test your blood sugar level at least every 4 hours while you are awake and check your urine for ketones. If ketones are present, call your doctor at once. If you have severe or prolonged vomiting, check with your doctor. Even when you start feeling better, let your doctor know how you are doing.