Inhalation of Insulin for Diabetes Management

The incessant rise of diabetes mellitus foretells the need for new management approaches. Subcutaneous insulin injections are the mainstay for type 1 diabetes and type 2 diabetes with poorly managed glucose levels. However, this route of administration is often associated with poor compliance. In the last two decades, the efficacy of inhaled insulin has been rediscovered, leading to the emergence of new insulin formulations, delivery devices, and regimens. The first inhaled insulin device, Exubera, was approved in the United States and Europe in 2006. The initial studies were encouraging and demonstrated efficacy like the fast-acting insulin and patient satisfaction likely to improve compliance. However, the bulky design of the inhaler, poor commercial planning, and concerns over the long-term effects of inhaled insulin on the lung tissue led to its withdrawal in 2007. Others also cancelled their inhaled insulin projects in the wake of the Exubera withdrawal, while a few continue their development. In 2014, Afrezza became the only inhaled insulin delivery system approved by the Food and Drugs Administration (FDA). The device design was user-friendly, and clinical trial results demonstrated that the inhaled insulin was non-inferior to the subcutaneous injection. Therefore, there is hope that inhaled insulin can contribute to diabetes management.