Inhaled human insulin.

Abstract

The benefit of subcutaneous insulin therapy in patients with diabetes is frequently limited due to difficulty in convincing patients of the importance of multiple daily insulin injections to cope effectively with meal-associated glycemic changes. Thus, the aim of achieving tight glycemic control, which is critical for reducing the risk of long-term diabetes-related complications, frequently remains elusive. The successful development of an inhalable insulin as a noninvasive alternative promises to change the management of diabetes. The first product to become available to patients is inhaled human insulin, a dry-powder formulation packaged into discrete blisters containing 1 or 3 mg of dry-powder human insulin and administered via a unique pulmonary inhaler device. It has recently been approved in both the United States and the European Union for the control of hyperglycemia in adult patients with type 1 or type 2 diabetes. The pharmacokinetic profile of inhaled human insulin closely mimics the natural pattern of insulin secretion, and resembles that of rapid-acting subcutaneous analogs. Similarly to rapid-acting subcutaneous analogs, inhaled human insulin has a more rapid onset of glucose-lowering activity compared to subcutaneous regular insulin, allowing it to be administered shortly before meals. It has a duration of glucose-lowering activity comparable to subcutaneous regular insulin and longer than rapid-acting insulin analogs. Inhaled human insulin effectively controls postprandial glucose concentrations in patients with type 1 or type 2 diabetes without increasing the risk of hypoglycemia, and even improves fasting glucose levels compared to subcutaneous insulin. Inhaled human insulin has an overall favorable safety profile. There are small reductions in lung function (1-1.5% of total lung forced expiratory volume in the first second [FEV1] capacity) after onset of treatment that are reversible in most patients if treatment is discontinued. Inhaled human insulin is associated with an increase in insulin antibody titers, especially in patients with type 1 diabetes. These increases are not associated with any clinical sequelae. Patient satisfaction data have shown that inhaled human insulin is associated with greater treatment satisfaction relative to subcutaneous insulin in patients with type 1 or type 2 diabetes. This review summarizes the current data on the clinical efficacy and safety of inhaled human insulin in patients with type 1 or type 2 diabetes.