On the use of dry powder inhalers in situations perceived as constrained.

Dose delivery from dry powder inhalers (DPIs) are dependent on the inhalation effort of the patient. Some patient groups, including asthmatic children, patients with acute asthma, and patients with advanced chronic obstructive pulmonary disease (COPD) are perceived as having problems in readily inhaling from a DPI in an efficient way; this opinion is based on alleged low inhalation flows. A review of the literature however shows that these groups can use a DPI in an efficient way and gain good clinical effect from its use. Particularly, it has been shown that children can generate a good peak inhalation flow through a DPI, albeit a lower inhaled volume. Similarly, patients with acute asthma can use a DPI in an efficient way, even reaching a better clinical effect with the DPI than with a pressurized metered dose inhaler with a spacer. Finally, it was shown that patients with severe COPD can generate the inhalation flows needed to generate an efficient drug aerosol from a DPI. Collectively, the discussed patient groups seem to perform as well as other subjects when it comes to their ability to generate an adequate inhalation flow through a DPI.