Background: In people with type 1 or type 2 diabetes, poor adherence to insulin therapy can compromise disease management. There are several reasons for poor adherence, including social embarrassment, inconvenience, needle anxiety, fear of injection pain, and complicated regimens. Attempts to facilitate implementation of insulin therapy and to improve treatment adherence have focused on expanding the choices and features of insulin delivery devices.
Objective: This review addresses the features, advantages, and disadvantages of insulin pen devices, with particular reference to FlexPen (Novo Nordisk, Bagsvaerd, Denmark), a prefilled/disposable pen device.
Methods: Data from clinical studies published through June 2005 that evaluated the safety or efficacy of FlexPen in patients with type 1 or type 2 diabetes were reviewed. Key studies were selected following assessment of the sponsor's reference collection and as a result of MEDLINE searches (key words: FlexPen and pen devices). Particular attention was paid to studies comparing the FlexPen device with other pen devices. Peer-reviewed journal articles and published conference papers were included in the evaluation, as were reviews addressing the general use of these devices in the treatment of diabetes and associated issues.
Results: Up to 65% of patients with type 1 or type 2 diabetes are not confident in their ability to effectively self-manage their disease. Only 23% of people with type 2 diabetes believe that insulin therapy would help them to better manage their disease. As many as 25% of people with diabetes who require insulin describe some anxiety regarding self-injection. Other barriers to effective insulin therapy include fear of injection pain, weight gain, and hypoglycemia; feelings of failure and guilt; and lack of motivation.
Conclusions: Insulin pen devices are discreet and offer patients convenience and flexibility. These features may give patients the confidence to overcome issues of needle anxiety and the social embarrassment associated with self-injection and, therefore, may lead to improved adherence to recommended insulin dosing schedules and compliance with multiple-injection regimens.