Insulin Delivery Systems: Reducing Barriers to Insulin Therapy and Advancing Diabetes Mellitus Treatment

https://doi.org/10.1016/j.amjmed.2008.03.025Get rights and content

Abstract

Insulin therapy is integral to the treatment of diabetes mellitus. Epidemiologic studies have shown its benefits both in terms of improving glycemic control and reducing the risk for long-term diabetic complications for both type 1 and type 2 diabetes. Despite these benefits, barriers to insulin therapy are well documented and include perceived inconvenience, needle anxiety, and portability of device. Historically, patients have often used a vial-and-syringe delivery system to inject a subcutaneous dose of insulin. However, modern regimens provide various choices of delivery systems for prescribers and patients, thus enabling treatment to be tailored to address most patient needs and concerns. Two key alternative delivery systems are now widely available: subcutaneous injection using a pen device, and subcutaneous insulin infusion. In the future inhalations systems for regular human insulin may also become available to patients. Developments in these insulin-delivery systems can improve patients' perceptions of, and experiences with, insulin therapy, potentially reducing barriers to insulin initiation in patients with type 2 diabetes, and also improving aspects of quality of life for those already on an insulin-based regimen.

Section snippets

Barriers to insulin initiation

Anxiety about needles and perceived injection pain is a well-documented barrier to insulin use. Patients with diabetes who require insulin treatment and suffer from profound injection-related anxiety are more likely to experience high levels of diabetes-related distress, psychological issues, and poor adherence to therapy.9 Unfortunately, needle-anxiety is widespread: a study investigating attitudes to injections in 400 young adults visiting a travel clinic found that 21.7% were afraid of

The development of insulin pens

Insulin pens were developed in 1985 as the first alternative to vials and syringes, and fall into 2 main categories: reusable (durable) and disposable (prefilled). Reusable pens require single-use cartridges that are replaced when empty. Disposable pens are prefilled, used, and then discarded. In particular, they offer the advantage of being factory calibrated, so there is no risk of introducing dosing error through reloading problems.17, 18 Multiple daily injection (MDI) regimens can also be

Insulin pumps and continuous subcutaneous insulin infusion

External insulin pumps are highly effective systems capable of providing constant subcutaneous insulin infusion (CSII) delivery. CSII is used in place of MDI, mostly among patients with type 1 diabetes. Only rapid–acting insulin analogues (aspart, glulisine, lispro) or regular human insulins are used in CSII pumps, and doses can be adjusted by the patient to give bolus delivery with food or to provide a low basal level of insulin between meals. A catheter is inserted into the subcutaneous

Inhaled insulin

The lungs are an effective route for insulin delivery, having a large surface area for absorption (100 m2), potential for rapid uptake, and onset of action after inhalation. New developments in asthmatic therapy have seen the production of more powerful inhalers that are able to propel insulin further into the lung, and manufacturers are now able to produce smaller aerosol particles—both of which help to optimize delivery.37 Inhaled insulins are designed to provide a “bolus” or mealtime dose,

Summary

Perceptions of insulin and its delivery have the potential to create strong barriers that limit initiation and intensification of treatment, depriving patients with diabetes of the benefits of improved glycemic control, and increasing the risk for developing future complications. Part of this psychological aversion to insulin may be owing to dislike of syringes. Modern insulin- delivery systems have been developed to be more user friendly, offering simpler, less painful, and more convenient

Author disclosures

The author of this article has disclosed the following industry relationships:

Stephen Brunton, MD, serves on advisory boards for Abbott Laboratories, Amylin Pharmaceuticals Inc., AstraZeneca, and Novo Nordisk A/S.

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    Statement of author disclosure: Please see the Author Disclosures section at the end of this article.

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