title: [Dry powder inhalers in extreme clinical situations].
abstract: BACKGROUND
  Dry powder inhalers (DPIs) require a certain threshold of inspiratory effort to generate respirable particles. We undertook a literature review to determine whether this may, in particular clinical settings (young children, elderly subjects, acute or chronic respiratory obstructive syndromes - asthma and COPD), constitute a limitation on their use.
  
  
  BACKGROUND
  Currently marketed DPIs exhibit different technical characteristics. Many factors may influence their efficacy, so that the predictive utility of in vitro tests is limited. Published clinical studies indicate that aerosol therapies inhaled with DPIs show clinical efficacy even at low inspiratory air flows in adults and children with acute asthma, in acute bronchoconstriction experimentally provoked by methacholine or histamine, in acute asthma attacks in adults and children, and in COPD-related airway obstruction. The efficacy of DPIs appears comparable to that of p-MDIs or nebulisation. However, the studies often have some limitations (including limited statistical power and patient selection) that may affect their value.
  
  
  CONCLUSIONS
  The published studies analysed suggest that DPIs may be used in the great majority of clinical situations, subject to careful patient education. Nevertheless, p-MDIs with spacers remain recommended by international guidelines for children under the age of 6.
  
  
  CONCLUSIONS
  Additional well-designed clinical studies remain desirable to establish firmly the efficacy of DPIs in these situations.
authors.affiliation: Service de Pneumologie et Réanimation, Hôpital de l'Hôtel-Dieu, Université Paris 5, France. nicolas.roche@htd.aphp.fr
authors.forename: N
authors.initials: N
authors.lastname: Roche
authors.forename: J F
authors.initials: JF
authors.lastname: Dessanges
authors.forename: J-C
authors.initials: JC
authors.lastname: Dubus
mesh_terms: D018927:Anti-Asthmatic Agents / Q000008:administration & dosage; D001249:Asthma / Q000188:drug therapy; D001993:Bronchodilator Agents / Q000008:administration & dosage; D006801:Humans; D009330:Nebulizers and Vaporizers; D011208:Powders; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy; D012138:Respiratory Therapy / Q000379:methods; D016896:Treatment Outcome
chemical_list: D018927:Anti-Asthmatic Agents; D001993:Bronchodilator Agents; D011208:Powders