[Inhaled insulin, new perspective for insulin therapy]

Since the discovery of insulin and its use in diabetes care, patients, physicians and nurses dream of another way of insulin administration than the subcutaneous injections actually used. Different types of insulin administration have been evaluated and, particularly, that using the pulmonary route. The use of this alternative method to deliver insulin may result in improved patient compliance, facilitate intensified therapies and avoid the delay of initiating insulin administration because patient's reluctance. The different insulin pulmonary delivering devices actually studied will be presented. Preliminary data comparing this way of administration and the subcutaneous injection of human regular insulin are good, but sufficient data comparing inhaled insulin with the new short-acting insulin analogues are not yet available. Among various difficulties of the pulmonary insulin delivery, the finding of an effective promoter, capable of increasing the bioavailability of insulin, is a crucial issue. The cost of such insulin administration might also be a problem. Finally, careful studies concerning the safety of this kind of administration, particularly potential long-term pulmonary toxicity, are mandatory. Nevertheless, inhaled insulin is an attractive topic in which most important pharmaceutical companies are currently involved.