title: Respiratory effect of beta-blockers in people with asthma and cardiovascular disease: population-based nested case control study.
abstract: Cardiovascular disease (CVD) is a common comorbidity in people with asthma. However, safety concerns have caused heterogeneity in clinical guideline recommendations over the use of cardioselective beta-blockers in people with asthma and CVD, partly because risk in the general population has been poorly quantified. The aim of this study was to measure the risk of asthma exacerbations with beta-blockers prescribed to a general population with asthma and CVD.
  
  
  
  Linked data from the UK Clinical Practice Research Datalink was used to perform nested case-control studies among people with asthma and CVD matched on age, sex and calendar time. Adjusted incidence rate ratios (IRR) were calculated for the association between oral beta-blocker use and moderate asthma exacerbations (rescue oral steroids) or severe asthma exacerbations (hospitalisation or death) using conditional logistic regression.
  
  
  
  The cohort consisted of 35,502 people identified with active asthma and CVD, of which 14.1% and 1.2% were prescribed cardioselective and non-selective beta-blockers, respectively, during follow-up. Cardioselective beta-blocker use was not associated with a significantly increased risk of moderate or severe asthma exacerbations. Consistent results were obtained following sensitivity analyses and a self-controlled case series approach. In contrast, non-selective beta-blockers were associated with a significantly increased risk of moderate asthma exacerbations when initiated at low to moderate doses (IRR 5.16, 95% CI 1.83-14.54, P = 0.002), and both moderate and severe exacerbations when prescribed chronically at high dose (IRR 2.68, 95% CI 1.08-6.64, P = 0.033 and IRR 12.11, 95% CI 1.02-144.11, P = 0.048, respectively).
  
  
  
  Cardioselective beta-blockers prescribed to people with asthma and CVD were not associated with a significantly increased risk of moderate or severe asthma exacerbations and potentially could be used more widely when strongly indicated.
authors.affiliation: Quality, Safety & Informatics Group, Division of Population Health Sciences, School of Medicine, University of Dundee, Mackenzie Building, Dundee, DD2 4BF, UK. d.r.z.morales@dundee.ac.uk.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Morales
authors.affiliation: Scottish Centre for Respiratory Research, School of Medicine, University of Dundee, Dundee, UK.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Lipworth
authors.affiliation: Dundee Epidemiology and Biostatistics Unit, Division of Population Health Sciences, School of Medicine, University of Dundee, Dundee, UK.
authors.forename: Peter T
authors.initials: PT
authors.lastname: Donnan
authors.affiliation: School of Medicine, University of Central Lancashire, Preston, UK.
authors.forename: Cathy
authors.initials: C
authors.lastname: Jackson
authors.affiliation: Quality, Safety & Informatics Group, Division of Population Health Sciences, School of Medicine, University of Dundee, Mackenzie Building, Dundee, DD2 4BF, UK.
authors.forename: Bruce
authors.initials: B
authors.lastname: Guthrie
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D001249:Asthma / Q000139:chemically induced* / Q000453:epidemiology; D002318:Cardiovascular Diseases / Q000188:drug therapy*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male
chemical_list: D000319:Adrenergic beta-Antagonists
keywords: Asthma; Beta-blocker; Cardiovascular disease; Drug safety; Pharmacovigilance