title: What is new with the beta2-agonists: issues in the management of asthma.
abstract: OBJECTIVE
  To review the more recent literature addressing the issue of whether beta2-agonists can worsen asthma and/or increase the risk of severe exacerbations and death from asthma.
  
  
  METHODS
  PubMed was searched (2001-December 2004), along with the Food and Drug Administration and Cochrane Library Web sites. In addition, the bibliographies of recent reviews of the subject were assessed.
  
  
  METHODS
  Randomized clinical trials, retrospective and prospective cohort studies, and meta-analyses published in the past 3 years were reviewed. Studies assessing the potential for beta2-agonists to worsen outcomes in asthma as well as long-term studies assessing asthma outcomes that included an arm with regular administration of short- or long-acting inhaled beta2-agonists (LABAs) were selected. Worsening asthma was defined as a decline in lung function, an increase in bronchial hyperresponsiveness, exacerbations, or death. Studies older than 3 years selected from the bibliographies of the primary articles that addressed background perspective were also included where appropriate.
  
  
  RESULTS
  The studies fell into 3 primary categories with some overlap: those assessing toxicity of the S-enantiomer of albuterol, those evaluating the risk of specific genotypes regarding worsening asthma, and those assessing asthma outcomes with LABA therapy.
  
  
  CONCLUSIONS
  The current data on the use of beta2-agonists continue to support the national and international guidelines for the treatment of asthma. That is, short-acting inhaled beta2-agonists should only be used as needed for symptoms and prevention of exercise-induced bronchospasm, and LABAs should only be used regularly as adjunctive therapy with inhaled corticosteroids in patients whose asthma is not controlled with low to medium doses of the inhaled corticosteroid.
authors.affiliation: Department of Pediatrics, Pediatrics/Pulmonary, MSC10-5590, 1 University of New Mexico, Albuquerque, NM 87131-0001, USA. hwkelly@salud.unm.edu
authors.forename: H William
authors.initials: HW
authors.lastname: Kelly
mesh_terms: D000280:Administration, Inhalation; D000318:Adrenergic beta-Agonists / Q000009:adverse effects / Q000627:therapeutic use; D000420:Albuterol / Q000009:adverse effects / Q000627:therapeutic use; D018927:Anti-Asthmatic Agents / Q000009:adverse effects / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy*; D002986:Clinical Trials as Topic; D006801:Humans; D011110:Polymorphism, Genetic; D018343:Receptors, Adrenergic, beta-2 / Q000187:drug effects / Q000235:genetics
chemical_list: D000318:Adrenergic beta-Agonists; D018927:Anti-Asthmatic Agents; D018343:Receptors, Adrenergic, beta-2; D000420:Albuterol