The science behind Exubera ®

Fear of needles constitutes a significant barrier to the use of insulin. Lung tissue offers a large permeable surface for rapid and predictable absorption of insulin into the bloodstream. Exubera insulin was the first inhaled insulin to be approved and marketed for clinical use. The present review is intended to summarize the data to present with Exubera insulin. The pharmacodynamic effect of this inhaled insulin is similar to that of injected regular human insulin. There are small changes in lung function that parallel age‐related changes in patients who are not taking inhaled insulin. Cough occurs frequently but does not affect the overall insulin effect. Patients who start using insulin gain weight, but there is less weight gain with Exubera use than with comparable doses of injected insulin. In multiple studies, the incidence of hypoglycemia with Exubera is similar to that with regular insulin. There is concern that insulin may act as a growth factor on the lung epithelium. Recently, analysis of existing data showed that six patients on Exubera developed lung cancer compared to only one on comparator injectable insulin, all cases occurred in former smokers. However, studies were not powered for this safety issue and numbers were too small to conclude a causal relationship between Exubera exposure and occurrence of lung cancer. Pfizer decided to discontinue marketing Exubera on October 18, 2007. The decision was based upon failure to meet financial landmarks rather than due to concern about possible safety issues. Drug Dev Res 69:130–137, 2008. © 2008 Wiley‐Liss, Inc.