What patients cannot use DPIs?
Answers
DPIs
DPIs rely on air drawn through the device to pick up powder from a container and carry it into the lungs within the same airstream.24 Some devices require insertion of drug capsules designed to release all the powdered content into the airstream. Other devices contain multiple doses taken from a reservoir or multiple prefilled blisters/cartridges of drug powder.24 These do not require the user to carry packets of separate drug capsules, but function is otherwise similar to single-capsule devices.
Inhalation flow rate through the device is critical to the successful operation of all DPIs, and the inspiratory effort required to deliver the drug to the lungs depends on the device. Not all patients are capable of creating sufficiently controlled inspiratory effort every time, especially during an exacerbation.30 New DPI devices are beginning to address this important issue, including the dose protector of the NEXThaler® (Chiesi Limited, Manchester, UK), which prevents release of the dose until sufficient flow rate is achieved,31 and the electronic power-assisted DPIs (active DPIs) currently in development.5