If your blood glucose levels are high, you might be using your insulin pen wrong


Insulin is required for people with type 1 diabetes and sometimes for people with type 2 diabetes. Many people who take insulin use an insulin pen. The correct insulin dose is dialed on the pen, the needle is inserted under the skin, and the insulin is injected though the needle once the button is pushed. The needle is disposable. So, after each injection, the used needle should be removed. A new disposable needle should be screwed onto the pen before each injection.

Pen needles come in various lengths, thicknesses, and types. If people with diabetes are giving themselves insulin, a standard pen needle that can be purchased from a pharmacy is often used. But if a healthcare provider is giving insulin to a patient, a safety needle is often used on the pen.

A safety needle is quite different than a standard needle. A safety needle (Figure 1) has a needle shield over it to protect a healthcare providers from accidentally sticking themselves with the used needle. Once the outer cover of the safety needle is removed, the plastic needle shield still covers the needle. As the pen is held against the skin, the plastic needle shield slides back and allows the needle to puncture the skin and the insulin to be injected by pressing the button. Once the injection is given, the plastic needle shield slides back over the needle as it is pulled out of the skin. The shield locks in place so the needle cannot be used again. This prevents healthcare providers from accidentally sticking themselves with the used needle.         insulin figures

The standard needle (Figure 2) looks a lot like the safety needle. It, too, has an outer cover. Once the cover is removed, the plastic cap over the needle looks like the plastic shield over the safety needle. However, the plastic cap over the standard needle MUST BE REMOVED before the injection to allow the needle to puncture the skin and the insulin to be injected. It does not automatically slide back when pressed against the skin, unlike the needle shield over the safety needle.

Many insulin users are taught to use an insulin pen by a healthcare provider who may be required to use a needle with a safety shield. It is dangerous for healthcare providers to use a standard needle, as they may stick themselves with the used needle when removing it. But, most people use a standard needle on the insulin pen at home. (Sticking yourself with a needle used to inject your own insulin poses no risk to you. But a healthcare provider who gets stuck with a used needle is at risk of catching diseases carried by the blood of the person who received the injection.)

Because a safety needle looks like a standard needle, some people have been confused if they were taught to give themselves injections using the pen with a safety needle. They mistakenly thought the needle cover would automatically slide back when it was pushed against the skin, just like the shield on the safety needle. This happened recently to a patient who had been taught to use an insulin pen while in the hospital. Nurses and a certified diabetes educator showed her how to use an insulin pen at home and how to test her blood glucose levels using a glucose meter. After she was discharged from the hospital, she reported high blood glucose levels to a visiting nurse. The nurse asked the patient to demonstrate how she was using the insulin pen. It turns out, she was not removing the cap from the standard needle. She thought she was using the same type of needle (a safety needle) that had been used on the insulin pen during her hospitalization. Thus, she was not receiving any insulin with each “injection.” The needle never punctured the skin because the cap directly over the needle had not been removed.

Here’s what you can do: If you are giving yourself insulin using an insulin pen, be sure you know what type of needle you are using with the pen—a safety needle or a standard needle. Most people will be given a standard needle to use at home. However, sometimes a doctor will prescribe a safety needle for patients who are “needle phobic,” or extremely afraid of needles. With safety needles, the needle itself is never visible to the person using the insulin pen. However, in most cases, a standard needle will be used with insulin pens in the home.

If you use a standard needle on an insulin pen, remove BOTH the outer cover and the needle cover so you can actually see the needle before injection. To test that you have placed the needle on the pen correctly, dial a “test” dose of 2 units on the pen. Then, WITHOUT inserting the needle under the skin, just WATCH the tip of the needle while pressing the injection button on the pen. You should see at least one drop of insulin come out of the tip of the needle. If you do not see any insulin coming out of the needle, the needle may not be attached correctly or your pen may be low on insulin. This step can also alert you if you forgot to remove the needle cap.

Once the “test” has confirmed that insulin is coming out of the needle, your pen is ready to use. Dial the insulin pen to deliver the amount of insulin you need to take. Insert the pen needle under the skin, press the injection button and wait a few seconds (length based on the pens’ directions), then remove the pen. Be sure to follow the specific directions for your pen. After the injection, remove the needle and discard it safely. Do not leave the needle attached to the pen between injections.

If you have any questions about using an insulin pen, contact your pharmacist or diabetes educator. Also, let your doctor know if your blood glucose levels remain high after injection of the insulin. You may need to confirm that you are using the pen correctly.

Created on March 1, 2018

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