Insulin pens are used by people with diabetes to inject insulin. The pens include an insulin cartridge, a dial to measure dosage, and a disposable needle.
Insulin pens are growing in popularity. They allow insulin to be delivered in a more simple, accurate, and convenient way than the vial and syringe method.
Types of insulin pen
There are several different brands and models of insulin pen available. Most fall into two distinct categories: disposable and reusable.
- A disposable pen: this contains a pre-filled insulin cartridge. Once used, the entire pen unit is thrown away.
- A reusable pen: this contains a replaceable insulin cartridge. Once empty, the cartridge is discarded and a new one put in.
A new disposable needle must be used every time insulin is injected. With proper care, reusable insulin pens can last for several years.
Choosing an insulin pen
The brand, model, and category of pen used will depend on several factors. It is important to discuss this with a doctor before purchase.
Some general factors about the pen to consider include:
- type and brand of insulin available
- size of the insulin dose it can hold
- increments by which the dose of insulin can be adjusted
- material and durability (if reusable)
- how it indicates remaining insulin levels
- ability to correct dose levels that are put in wrong
- size of the numbers on the dose dial
- level of dexterity required to use the pen
Research has highlighted the benefits of using insulin pens, particularly prefilled disposable pens. People with diabetes are happier using insulin pens than the vial and syringe technique, according to some studies.
One reason for this is that insulin pens have many features that make them safe and convenient. For example, greater dose accuracy and auto-shield needles. Other research shows that those using pens are more than twice as likely to be able to read the dosing scale. This is compared with those using the vial and syringe method.
Some other advantages include:
- ease of use, particularly for older adults and children
- ability to fine-tune and deliver highly accurate doses
- portable, discreet, and convenient nature of the pens
- small and thin needle sizes that reduce fear and pain
- ability to accurately pre-set doses using a dial
- time-saving benefits due to prefilled and pre-set insulin levels
- memory features to show when and how much the last dose was
- range of accessories to allow for easier storage and use
Although there are many benefits to insulin pens, there are also some drawbacks. These include:
- not all types of insulin can be used
- not possible to mix two different types of insulin
- can only be used for self-injection
- more expensive than the vial and syringe method
- some insulin is wasted with each use
- not universally covered by health insurance carriers
How to use insulin pens
It’s important to follow the instructions closely as insulin pens vary slightly in how they are used. People who have never used an insulin pen before may need to get advice from their doctor before first use.
A general guide for using insulin pens is as follows:
- If using a new pen, take it out of the refrigerator 30 minutes before use.
- Check the expiration date.
- Check the insulin is the correct type and strength.
- If necessary, insert a new cartridge into a reusable pen.
- Mix the insulin by gently rolling the pen between the palms of the hands.
- Tilt the pen up and down until the insulin is clear and smooth.
- Wash hands.
- Remove the pen cap and clean the top with alcohol.
- Firmly attach a new needle to the pen.
- Remove the needle caps (retaining the outer cap).
- Turn the dial to the correct dose.
- Double-check the dose before injecting.
- Clean the chosen injection site with alcohol and allow to dry.
- Do not inject into areas which have wounds or bruising.
- If possible, vary the injection site to avoid lumps or swelling.
- Hold the pen to the injection site as per instructions.
- Press the injection button.
- Wait 10 seconds before removing the needle from the skin.
- Press on the injection site for 5 to 10 seconds, but do not rub the skin.
- Remove and safely dispose of the needle.
- Replace the cap on the pen.
Unopened insulin and new insulin pens need to be kept in the refrigerator. However, once opened they can be kept at room temperature and out of direct sunlight.
Open insulin may be kept at room temperature for 28 days but it is recommended to keep unopened insulin in the refrigerator.
According to the American Diabetes Association, insulin kept at room temperature will last approximately 28 days.
However, it depends on the type of insulin the pen contains. As such, it is always important to check the expiration date and follow the device instructions for storage and use. Expired or improperly stored insulin may not be as effective as it should be. Insulin pens should never be stored with the needle attached, even if it is a new needle. This can affect how sterile the needle is, and may interfere with the insulin dose given.