Insulin pens

Overview

Insulin pens are injection devices designed to administer preloaded insulin into the subcutaneous tissue, facilitating insulin administration. They are a form of insulin therapy for individuals with diabetes and are categorized as a type of multiple daily injection (MDI) system.

An insulin pen resembles a regular writing pen but has a single-use needle at the tip and contains insulin. Various types of insulin pens are available, including advanced “smart” or connected models. Your healthcare provider will explain the details and usage of these devices.

While insulin pens come in various types, they all share several key components:

• Insulin reservoir: This clear plastic chamber stores the insulin, allowing you to monitor its clarity and remaining amount. Some pens feature replaceable insulin cartridges, while others are disposable and must be discarded once empty.
• Pen cap: The cap safeguards the insulin reservoir from damage when the pen is not in use.
• Rubber seal: This is the section where you attach a single-use needle for injections.
• Needle: Insulin pen needles are designed for single use only. Each needle is packaged in a sterile container, which you remove before attaching the needle to the pen. Needles come in various sizes, so consult your healthcare provider to choose the one that suits you best.
• Dosage knob: This knob allows you to set the desired insulin dose.
• Dosage window: This display shows the number of insulin units selected with the dosage knob.
• Injection button: After attaching the needle, pressing this button administers the insulin dose.
• Label: The label provides information about the type and brand of insulin in the pen, as well as its expiration date.

Types

There are various types of insulin pens available, and they can be recognized by:

• Disposable: Disposable pens are designed to be discarded after the insulin reservoir is depleted or expires.
• Reusable: Reusable pens allow you to replace the insulin cartridge with a new one, enabling you to continue using the same pen.
• Type of insulin used: Insulin pens are tailored to specific types of insulin, such as long-acting, rapid-acting, intermediate-acting, or short-acting insulins. Some pens are compatible with mixed insulin types, depending on the manufacturer’s specifications.
• Digital features: Insulin pens may be equipped with digital components. “Smart” or “connected” pens sync with a mobile app to track insulin usage, recording details like injection times and amounts. These pens might also provide additional functions such as:
  • Monitoring active insulin levels.
  • Calculating bolus doses based on current blood sugar levels and carbohydrate intake, with some systems connecting to continuous glucose monitors (CGMs).
  • Sending alerts for missed injections around typical mealtimes.
  • Tracking insulin temperature and expiration dates.

Other pens, referred to as “manual,” lack digital features, requiring you to manually log your insulin doses. Consult your healthcare provider to explore the options and benefits of smart insulin pens.

Reasons for undergoing the procedure

Choosing insulin pens is a sensible option for using insulin to manage diabetes. The process may seem intimidating at first because there is such a large range of pens available. That being said, your healthcare provider will help you choose the best insulin pen for your needs.

Risk

The potential risks associated with using insulin pens include:

• Cost: Insulin pens may be more expensive compared to syringes and insulin vials.
• Frequency of Injections: Insulin pens still require multiple daily injections, which can lead to more frequent skin bruising compared to insulin pump therapy.

Additionally, a common risk of any insulin injection, including insulin pens, is hypoglycemia (low blood sugar). This occurs when blood sugar levels drop below 70 milligrams per deciliter (mg/dL).

It is important to be aware of how to manage low blood sugar before starting insulin therapy.

Before the procedure

Before administering an injection, set up a clean, dry workspace. Ensure you have the following supplies:

• Insulin pen: Use the prescribed insulin pen, and if you have multiple pens, confirm you select the correct one for your specific needs.
• Pen needle and alcohol wipe: Prepare a pen needle and an alcohol wipe for sterilization.
• Sharps disposal container: Have a container ready for disposing of used needles. This can be a hard plastic container with a secure lid or a commercial “sharps” container.

Follow these step-by-step instructions to prepare your insulin pen:

• Wash your hands: Start by thoroughly washing your hands to ensure cleanliness.
• Remove the cap: Take off the cap from the insulin pen.
• Check the insulin: If the insulin appears cloudy, gently roll the pen between your hands and turn it from side to side for one full minute. If the insulin is clear, no rolling is necessary. Avoid shaking the pen.
• Wipe the rubber stopper: Clean the rubber stopper on the pen with an alcohol wipe.
• Attach the needle: Remove the paper tab from the new pen needle. Screw the needle onto the pen, then remove the outer needle cap, which you will need for later needle removal. Also, remove the inner needle cap.
• Prime the pen: To remove air bubbles and ensure proper functioning, you must prime the pen before each use. Turn the dosage knob to the 2 units mark. With the pen pointed upward, push the knob fully to expel a drop of insulin. Repeat this step until a drop of insulin appears.
• Set the dose: Adjust the dosage knob to select the prescribed amount of insulin.
• Verify the dose: Confirm that the dosage is correct, then set the pen down, ensuring the needle does not touch any surfaces.

During the procedure

The following are the detailed instructions for giving an injection with an insulin pen:

• Hold the pen: Using your dominant hand, grip the insulin pen firmly, leaving your thumb free to press the injection button.
• Insert the needle: Quickly insert the needle into your skin at a 90-degree angle, ensuring it is fully inserted.
• Deliver the dose: Slowly press the injection button all the way to release the full dose of insulin. Maintain pressure at the injection site for 6 to 10 seconds before withdrawing the needle.
• Dispose of the needle: Carefully replace the outer needle cap, then unscrew the needle (the cap should come off with the needle). Dispose of the needle in your designated sharps container.
• Store the pen: Reattach the pen cap and store the pen at room temperature.

If you experience bleeding at the injection site, apply gentle pressure with a clean alcohol wipe or cotton ball. If needed, cover the site with a bandage.

Recommended sites for insulin pen injections include:

• Buttocks.
• Front and side of your thighs.
• Lower belly.
• Upper and outer arms.

Avoid injecting in the following areas:

• Within 2 inches (5 centimeters) of your belly button.
• Middle part of your abdomen.
• Scar tissue or stretch marks
• Near joints.
• Groin area.

It’s important to rotate your injection sites to prevent complications. Repeated use of the same site can lead to hardened areas under the skin (lipohypertrophy) or lipodystrophy, which involves abnormal fat distribution or loss in the injection area. These issues can affect insulin absorption and effectiveness.

By rotating your injection sites, you ensure injections remain effective, safe, and comfortable. If you must inject in the same area, make sure to choose a spot at least 1.5 inches away from the previous injection site. Additionally, insulin absorption can vary depending on the injection site and the type of insulin used.

After the procedure

After injecting insulin, hold the insulin pen in place for 6 to 10 seconds to ensure proper absorption before removing the needle from your skin.

Dispose of each used needle in a designated “sharps” container for safe disposal. If you’re using a disposable insulin pen, discard the pen (without the needle) in your regular trash once the insulin is depleted or expired.

Outcome

Insulin pens are often easier to use than traditional syringes and vials, especially for those who find it difficult to handle drawing insulin. Pens provide greater convenience, and studies show they offer better dosing accuracy and consistency. Some people also prefer insulin pens over insulin pumps, as they don’t require being connected to a device. For storage, open insulin pens should be kept at room temperature, ideally between 68- and 72-degrees Fahrenheit (20 to 22 degrees Celsius), and away from extreme heat or cold, which could affect the insulin’s effectiveness. Unopened pens should be refrigerated and used before their expiration date. Once opened, most pens stay effective for about 28 days, so it’s important to note the date of opening on the pen itself.

When starting with insulin pens, your healthcare provider or a certified diabetes care and education specialist (CDCES) will typically guide you through the process. Be sure to ask any questions during the training session. Regular follow-ups with your diabetes provider are essential to ensure your treatment remains effective and to make any necessary adjustments if you encounter frequent high or low blood sugar levels.