Initiating insulin therapy in type 2 diabetes: benefits of insulin analogs and insulin pens.

Despite the development of alternative therapies in recent years, insulin injections remain essential treatment for type 2 diabetes once oral therapy alone becomes inadequate. However, neither patients nor physicians are proactive enough with regard to starting insulin, despite the well-known benefits of early insulin initiation and aggressive dose titration. Barriers to starting insulin therapy are being overcome by developments in insulin and delivery device technology and are the subject of this review. A literature search spanning the last 25 years was carried out to identify publications addressing issues of insulin initiation, how insulin analogs can help overcome barriers to initiation, and the advantages of pen-type insulin delivery systems. Seventy-five publications were identified. These references illustrate that the drawbacks associated with regular exogenous human insulins (soluble and NPH) are improved with modern insulin analogs. The more rapid absorption of prandial insulin analogs compared with human insulin eliminates the need for an injection-meal-interval, increasing convenience, while basal analogs have no discernible peak in activity. Modern insulin delivery devices also have advantages over the traditional vial and syringe. Currently available insulin pens are either durable (insulin cartridge is replaceable; e.g., HumaPen, Eli Lilly [Indianapolis, IN]; NovoPen series, Novo Nordisk [Bagsvaerd, Denmark]) or disposable (prefilled; e.g., FlexPen, Novo Nordisk; SoloSTAR, sanofi-aventis [Paris, France]), with features to aid ease-of-use. These include a large dose selector, dial-up and dial-down facility, and audible clicks when selecting the dose. The potential for dosing errors is thus reduced with pen-type devices, with other benefits including a discreet appearance, ease of learning, and greater user confidence. Collectively, these features contribute to overwhelming patient preference when compared with vials and syringes. Despite the greater cost of insulin pens relative to vials and syringes, improvements in treatment adherence with pens-and hence glycemic control-may offset these costs in the long term.