Insulin inhalers may be getting closer to becoming available, with the recent publication of a “proof of concept” study in the respected British medical journal, The Lancet. Researchers reported last month that patients with type 1 diabetes who received their insulin via inhaler achieved and sustained blood glucose control equal to those receiving insulin by traditional injections. Inhalers utilize short-acting insulin and so cannot replace all injections, but they can substitute for all but 1 or 2 injections of long-acting insulin.

In the study, 35 patients inhaled insulin doses immediately before meals, using a dry powder insulin formulation and an aerosol delivery system. The powdered insulin is packaged in individual blisters; the blister is opened within the inhaler, and the powder then dispersed by the inhaler into a discrete aerosol cloud, which is captured in a holding chamber. The patient inhales the aerosol bolus. Those in the inhaler group also received subcutaneous injections of insulin at bedtime.

The inhaled insulin was well tolerated, with no serious adverse effects reported. Not surprisingly, those patients receiving the inhaled insulin reported that it was easier to use, more comfortable and convenient, and less difficult than injections. Patients on subcutaneous insulin therapy, however, were less self-conscious about taking insulin away from home. Additional larger-scale studies are under way to further test the viability of inhaled insulin therapy.