title: Prescribing of β-adrenoceptor antagonists in asthma: an observational study.
abstract: BACKGROUND
  β-Antagonists have recently been proposed for the treatment of chronic asthma; however, concerns regarding risk of acute bronchoconstriction in clinical trials remain.
  
  
  OBJECTIVE
  To determine the frequency of oral β-blocker prescribing in patients with asthma and associations with severe asthma exacerbations requiring oral steroids in patients with active asthma defined by prior asthma-related medication use.
  
  
  METHODS
  Patients with asthma registered on 31 March 2007 and all asthma-related medications from the preceding 2 years were identified from anonymised clinical data from one-third of Scottish general practices. The main outcome measure was the relative incidence of active asthma patients receiving oral steroids following a new oral β-antagonist prescription.
  
  
  RESULTS
  Of the 53,994 adult patients identified with asthma 1527 (2.8%; 95% CI 2.69% to 2.97%) patients were prescribed an oral β-antagonist of which 441 (28.9%, 95% CI 26.7% to 31.2%) had active asthma and received a new β-blocker prescription. The average number of patients prescribed rescue steroids at baseline in 367 patients with sufficient follow-up was 3.4 (0.9%) patients every 2 weeks. Rescue steroids were prescribed to 3 (0.8%) patients in the first 2 weeks and to 3 (0.8%) patients in the second 2 weeks following the new oral β-antagonist (incidence rate ratio (IRR) 0.87, 95% CI 0.25 to 2.99 and IRR 0.89, 95% CI 0.26 to 2.97, respectively). No significant difference was found following stratification for β-antagonist selectivity.
  
  
  CONCLUSIONS
  These results suggest that prescribing new oral β-blockers for the purpose of investigating potentially beneficial effects of chronic treatment would not lead to large increases in patients treated with oral steroids acutely in general practice.
authors: School of Medicine, University of St. Andrews, St Andrews, Fife, UK.
authors: Daniel R
authors: DR
authors: Morales
authors: Bruce
authors: B
authors: Guthrie
authors: Brian J
authors: BJ
authors: Lipworth
authors: Peter T
authors: PT
authors: Donnan
authors: Cathy
authors: C
authors: Jackson
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D018927:Anti-Asthmatic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy* / Q000453:epidemiology; D004334:Drug Administration Schedule; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D004363:Drug Utilization / Q000706:statistics & numerical data; D005194:Family Practice / Q000706:statistics & numerical data; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D012606:Scotland / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000319:Adrenergic beta-Antagonists; D018927:Anti-Asthmatic Agents; D005938:Glucocorticoids