For over 80 years exogenous insulin has been given by injection. The injection devices have improved—disposable syringes and pen injection devices are more convenient and less traumatic than the boil to sterilise, use until too blunt devices of yesteryear—but patients and healthcare professionals remain uneasy about the concept of injections. Yet the evidence based drive for increasingly tight glycaemic control means that more patients should be offered more injections. A recent attempt to circumvent the need for injection that may soon hit a clinic near you is the use of the lung as an absorption pathway, with the development of insulins to be taken by inhalation. Two versions, a powder and an aerosol, may be nearing launch.

Insulin can be effective given by inhalation. This was first shown in 1971, although the early work was not pursued, and it was not until 2000 that the modern era of inhaled insulin began.1 2 The bioavailability is 10-15% and the dose equivalent about three times that of injected insulin. The pharmacodynamics of inhaled insulin offer an action profile with a fast onset (although slightly …