[Inhaler therapy for adults with obstructive lung diseases: powder or aerosol?].

When prescribing inhalation medication in the ambulant treatment of patients with asthma and chronic obstructive pulmonary disease (COPD), a choice can be made between dry powder inhaler (DPI) and pressurized metered dose inhalers (pMDI). The degree of deposition in the lower airways depends on the dose delivery via the inhaler and the mean diameter of the released particles (MMAD). With a DPI, dose delivery and MMAD depend on the inspiratory flow rate. With a pMDI dose delivery and MMAD do not depend on the inspiratory flow rate but on hand-mouth co-ordination. The main determinants for the choice of a DPI or a pMDI are the degree of co-operation and co-ordination, and the inspiratory flow rate of the patient.