Are inhaled systemic therapies a viable option for the treatment of the elderly patient?

Although inhalation has been used as a route for the delivery of systemic drugs for millennia, the recent emergence of fine milling and nano-technology methods has extended the range of potential therapies that can be absorbed from the alveolar surface. Administration of insulin by inhalation has attracted particular attention. However, there has been very little research into the pharmacokinetic and pharmacodynamic characteristics of such new inhaled substances in elderly patients and the effects of lung aging and co-pathologies are not known, particularly in the very old. Furthermore, it has been shown that the decrements in cognition, praxis and executive function that are highly prevalent in frail elderly people have a profoundly detrimental effect on inhaler technique. Consequently, it is likely that a large proportion of elderly patients would not be able to use drugs targeted for alveolar absorption because accurate and reliable inhalation performance would not be achieved. On the other hand, it is expected that cognitively intact older people with good neurological, pulmonary and musculoskeletal performance would be able to use inhaled treatments in the same manner as younger individuals. In frail old age, and in patients with unreliable deep inhalation techniques, there might be more scope for the use of inhaled preparations for mucosal absorption from the nasal passages and upper airways. Indeed, the number of drugs under consideration for that mode of application is growing. This article focuses on the potential use of inhaled systemic treatments in old age and the physical and cognitive problems that might limit their use in that group of patients.