title: Targeting drugs to the airways: The role of spacer devices.
abstract: OBJECTIVE
  Spacer devices are inhalation aids of varying dimension and complexity, specifically designed to overcome problems with the use of pressurised metered dose inhalers (pMDIs). The aim of this review is to examine the current understanding about these inhalation devices and discuss their advantages and disadvantages.
  
  
  METHODS
  The pertinent literature concerning the characteristics and effects of spacers on delivery and lung deposition of inhaled medications, as well as their clinical efficacy in patients with reversible airway obstruction, is examined.
  
  
  RESULTS
  Spacers minimise problems of poor inhalation technique with pMDI, reduce oropharyngeal deposition and increase lung deposition. Spacers improve the clinical effect of inhaled medications, especially in patients unable to use a pMDI properly. Compared to both pMDIs and dry-powder inhalers, spacers may increase the response to beta-adrenergic bronchodilators, even in patients with correct inhalation technique. A pMDI plus spacer has proven to be viable lower cost alternative to the use of a nebuliser for delivering large bronchodilator doses in patients with severe acute asthma or chronic obstructive pulmonary disease. The use of large-volume spacers is recommended for delivering high doses of inhaled corticosteroids, and may permit a lower maintenance dose to be used.
  
  
  CONCLUSIONS
  pMDIs may be routinely fitted with a spacer, especially in situations where correct pMDI use is unlikely.
authors.affiliation: Università degli Studi di Firenze, Dipartimento di Area Critica Medico Chirurgica, Firenze, Italy. f.lavorini@dac.unifi
authors.forename: Federico
authors.initials: F
authors.lastname: Lavorini
authors.forename: Giovanni A
authors.initials: GA
authors.lastname: Fontana
mesh_terms: D000280:Administration, Inhalation; D000336:Aerosols; D000402:Airway Obstruction / Q000188:drug therapy; D016503:Drug Delivery Systems; D006801:Humans; D036503:Inhalation Spacers; D008168:Lung / Q000378:metabolism; D008173:Lung Diseases, Obstructive / Q000188:drug therapy; D009330:Nebulizers and Vaporizers / Q000191:economics; D004364:Pharmaceutical Preparations / Q000008:administration & dosage; D014018:Tissue Distribution
chemical_list: D000336:Aerosols; D004364:Pharmaceutical Preparations