Environmental impact of pressurised metered dose inhalers versus dry powder and soft mist inhalers at a tertiary Melbourne hospital.

The carbon footprint of devices to deliver inhaled respiratory medications has come into focus as climate change has been identified as a worldwide emergency. Metered dose inhalers (MDIs) contain hydrofluorocarbons that have significant global warming potential compared to dry powder inhalers (DPIs) and soft mist inhalers (SMIs), which do not use a propellant gas. A 12-month pharmacy inpatient dispensing audit demonstrated that inpatient MDI use significantly outweighed that of DPIs and SMIs and accounted for approximately 99% of inhaler-related greenhouse gas emissions at our hospital.