Insulin pens and syringes are the most commonly used device by diabetics for injecting insulin. Although injecting with the use of syringe is still the most predominant method, more people are seeing the benefits of using insulin pen device and pen needles. Insulin pens came out in mid 1980s when the only method known is through syringe injection. It was introduced by the company Novo Nordisk and marketed as Novopen.
An insulin pen is composed of an insulin cartridge that can either be part of the pen or bought separately, a dial that measures the dose and a pen needle that delivers the dose.
Pen needles used to be long and sharp. Thanks to advancements in technology, they are now small, thin and often painless. Universal pen needles fit almost all brands of pen. Pen needles come in different lengths, ranging from 5mm to 12.7 mm and thickness of 29 to 31 gauge. Don’t forget to replace your needles after every injection. Only choose pens and needles that conform to the ISO standard.
There are two types of insulin pen:
Durable (Reusable) – durable pens are often heavy because they are made of metal. It contains replaceable insulin cartridge, which is replaced by a new cartridge once emptied.
Prefilled (Disposable) – this type of pen comes with prefilled insulin. When the contents are gone or if the pen has been used more than the days allotted per package insert, it is simply thrown away. And you need to buy another prefilled pen. These pens are advisable to those with changing glucose control regimen, since most pens only supports a certain type of insulin. Your prefilled pen will no longer be usable if you are prescribed a different type of insulin in the future.
Pros of Using Insulin Pens
- - they are discreet, portable and convenient because you don’t need to bring a vial and a syringe. Best choice if you’re always on the go.
- - gives accurate dosage constantly
- - helpful to those with visual or fine motor skills impairment
- - needles are not dulled by second injection from vial to skin, thus reduces pain
- - some insulin pens have a record function that can save date, dosage and how much time has passed since the previous injection
Cons of Using Insulin Pens
- - you cannot mix different insulins in one pen
- - separate pens and needles may be expensive to some people
How to Choose Pen Needles
- 1. The length of your needle dictates the proper injection technique. The most common technique in injecting is vertically, at a 90 degrees’ angle. If you have longer needles, you need to pinch your skin at the site of injection to avoid pricking the muscle.
- 2. Thickness of skin is almost the same for everyone regardless of BMI. Most people use 4 mm – 5mm long needles. Obese patients may use up to 8 mm in length or less.
- 3. Choose needles that are compatible with your pens. Some brands make their needles compatible to a broad range of pens. Still, it’s best to check with your general practitioner.
- 4. Some device have auto shield function that hides the tip of the needle for those who are afraid to see actual needles poking their skin. Pen attachments can either be screw-on or click-on; patients with arthritis can benefit more from click-on pens.
- 5. Those who need large doses of insulin may choose pen needles with bigger inner diameters, so that large dose volumes will flow quickly. Other brands like BD medical uses thin-wall technology to facilitate the flow of insulin even in a small needle.