Dry Powder Inhalers: From Bench to Bedside

Dry powder inhalers (DPIs) are now widely prescribed and preferred by the majority of patients. These devices have many advantages over the traditional pressurized metered-dose inhaler (pMDI) but they do have disadvantages. The characteristics of the dose emitted from a DPI are affected by the inhalation manoeuvre used by a patient. Each patient is different and the severity of their lung disease varies from mild to very severe. This affects how they use an inhaler and so determines the type of dose they inhale. An understanding of the pharmaceutical science related to DPIs is important to appreciate the relevance of how patients inhale through these devices. Also, each type of DPI has its unique dose preparation routine, and thus it is essential to follow these recommended steps because errors at this stage may result in no dose being inhaled. All issues related to the inhalation manoeuvre and dose preparation are addressed in this chapter. The importance of the inhalation technique is highlighted with a realization of inhale technique training and checking. During routine patient management, devices should not be switched nor doses increased unless the patient has demonstrated that they can and do use their DPI.