OBJECTIVES To assess the potential financial and resource impact of patients with asthma or COPD being switched from pressurised metered-dose inhalers (pMDI) to dry powder inhalers (DPIs) in both a representative primary care network (PCN) of 50,000 population and the English National Health Service (NHS). The switch-away from inhalers containing fluorinated gas propellant (pMDIs) has been advocated for environmental reasons, despite these are an effective and common therapeutic

METHODS Current patterns of inhaler use in England and epidemiological data were used to model the resources and costs associated with implementing this switch. Three scenarios were modelled with varying assumptions of the patient acceptance of the transition and additional resources required for patient counselling and switch management should a switch occur.

RESULTS : 71% of asthma and 39% of COPD patients use pMDIs, while 3% of asthma and 16% of COPD use both inhaler devices. Additional costs to implement such switch ranged from £18K–£53K for a PCN, and from £21m–£60m for NHS depending on the assumptions. In a ‘gold standard’ approach, whereby switch is made depending on a person’s ability to use a particular device, patients should be appropriately supported by clinical pharmacists and practice nurses. This approach, which requires patients to attend a targeted initial and a follow-up appointment to be appropriately trained to use the alternative device is the most cost and resource intensive.

CONCLUSIONS Switching inhaler devices for environmental reasons alone is a complex activity that should be evaluated looking at individual and organisational factors. Targeted transition of inhalers must achieve a balance between environmental impacts, organisational factors and patient requirements. The cost and time implications for managing a switch can be substantial and should be considered by the health service in case this action is implemented, in order to appropriately counsel and support patients.