CLINICAL | DIABETES
Does size matter?
Insulin pens are growing in popularity, and many people with diabetes nowadays use a pen to administer insulin. The pens allow more simple, accurate and convenient delivery than using a vial and syringe.
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OT EVERY PERSON with diabetes will need to take insulin. However, those that do sometimes find that sticking to an insulin schedule can be demanding, disruptive and draining.Some people prefer insulin pens as a way to make taking insulin less intrusive and inconvenient. In this article, we look at the types of insulin pens, how to use them, and the benefits and disadvantages of choosing an insulin pen over a vial and syringe. TYPES Different brands and models of insulin pen are available. Most fall into two distinct categories: disposable and reusable. • A disposable pen: This contains a prefilled insulin cartridge. Once used, the entire pen unit is thrown away • A reusable pen: This contains a replaceable insulin cartridge. Once empty, a person discards the cartridge and installs a new one. A person must replace the disposable needle after each injection of insulin. With proper care, reusable insulin pens can last for several years. CHOOSING AN INSULIN PEN There are several factors to consider when choosing an insulin pen. Choosing a brand, model, and category of pen will depend on several factors. Discuss this with a doctor
20 MAY 2020 | MEDICAL CHRONICLE
before making any purchase. Some general considerations about the pen include: • The type and brand of insulin available • The size of insulin dose it can hold • The increments by which a person can increase the dose of insulin • Material and durability, if choosing a reusable pen • 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. Needle length and thickness are other considerations for choosing an insulin delivery product. Manufacturers measure the thickness of a needle using ‘gauge’. A gauge of 33 is thicker than a gauge of 22. Thicker gauges might cause more pain but also deliver insulin more quickly. Needles can be between four and 12.7 millimetres (mm) in length. A shorter needle might reduce the risk of accidentally injecting insulin into the muscle instead of the fat just under the skin, or subcutaneous fat. WHAT NEEDLES SHOULD BE USED FOR INJECTING INSULIN? Needles come with a different diameter and length. Those with a higher gauge number have a smaller needle diameter. Needles are available in 4-, 5-, 6- or 8mm. Needles with
a length of 12.7mm have an increased risk of intramuscular injection. It is often assumed that a heavier person, with a higher BMI, may require a longer needle. However, we now know that 4-, 5- or 6mm needles are suitable for all people with diabetes, regardless of their BMI. Studies have shown that shorter needles of 4mm are as safe and welltolerated in comparison to longer ones. Insulin therapy should ideally be started using shorter length needles and these injections should be given at 90 degrees to the surface of the skin. ADVANTAGES Insulin pens might also help people stick to their insulin therapy routine. Advantages include: • Ease of use, particularly for older adults and children • The ability of a person with diabetes to fine-tune and deliver highly accurate doses using an insulin pen • The portable, discreet and convenient nature of the pens • Small and thin needle sizes that reduce fear and pain • The ability to accurately pre-set doses using a dial • Time-saving benefits, due to prefilled and pre-set insulin levels • Memory features that recall the timing and amount of the previous dose
• A range of accessories to allow for easier storage and use. The ADA advises doctors to prescribe an insulin pen for people who have issues with finger dexterity problems and reduced vision. An insulin pen can support a more accurate dose of insulin than a vial and syringe. ‘Smart’ pens also exist that can calculate appropriate doses of insulin and provide a report on insulin usage for the user to download. SUMMARY While insulin pens might be more expensive than a vial and syringe, they are more convenient, less painful, and easily storable and transportable. They essentially combine the vial and syringe, allowing greater dose accuracy and easier administration of doses. Be sure to closely follow the instructions on the packaging and store insulin in a cool dry place once open. Insulin alone can help manage diabetes but maintaining a balanced diet and exercise regimen alongside any prescribed medications is an effective route to controlling blood sugar. Sources: Diabetes South Africa, Healthline.com
*The article is in no way linked to any advertising around it.
