title: Risk of arrhythmias associated with ipratropium bromide in children, adolescents, and young adults with asthma: a nested case-control study.
abstract: OBJECTIVE
  To evaluate the risk of arrhythmias associated with inhaled anticholinergic (IAC) use in young patients with asthma.
  
  
  METHODS
  Population-based nested case-control study.
  
  
  METHODS
  IMS LifeLink Health Plan Claims Database.
  
  
  METHODS
  Patients 5-24 years of age who were diagnosed with asthma and were new users of asthma controller medications were identified between July 1997 and April 2010. Cases were newly diagnosed with arrhythmia and were matched with up to 10 controls based on age, gender, geographic region, and quarter and year of first controller medication dispensing.
  
  
  RESULTS
  Exposure to IACs was determined in the 180 days prior to the event date, defined as date of arrhythmia claim. Active use was defined as sufficient days' supply of a prescription to extend through the event date. Among 283,429 patients with asthma, 7656 cases were matched to 76,304 controls. Most of those included were female (58.8%) and 12 years or older (73.3%). Active exposure of IACs was observed in 0.69% of cases and 0.18% of controls. Active use was associated with a 1.56-fold increase in arrhythmia risk compared with nonactive users or nonusers (adjusted odds ratio [ORadj ] 1.56, 95% confidence interval [CI] 1.08-2.25]). Risk was highest among active users of ipratropium (ORadj 1.59, 95% CI 1.08-2.33). Active high-dose users of IACs (more than 0.114 mg of ipratropium equivalents) had a 69% increase in risk (ORadj 1.69, 95% CI 1.10-2.59), whereas the added risk for active users receiving low-dose IACs (0.114 mg of ipratropium equivalents or less) was not statistically significant (ORadj 1.22, 95% CI 0.53-2.65).
  
  
  CONCLUSIONS
  Use of ipratropium bromide was associated with an increased risk of arrhythmias in 12-24-year-old patients with asthma.
authors.affiliation: Department of Pharmacy Systems Outcomes and Policy, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Sruthi
authors.initials: S
authors.lastname: Adimadhyam
authors.forename: Glen T
authors.initials: GT
authors.lastname: Schumock
authors.forename: Surrey
authors.initials: S
authors.lastname: Walton
authors.forename: Min
authors.initials: M
authors.lastname: Joo
authors.forename: Joanne
authors.initials: J
authors.lastname: McKell
authors.forename: Todd A
authors.initials: TA
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D001145:Arrhythmias, Cardiac / Q000139:chemically induced*; D001249:Asthma / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000009:adverse effects*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D009241:Ipratropium / Q000009:adverse effects*; D008297:Male; D012307:Risk Factors; D055815:Young Adult
chemical_list: D001993:Bronchodilator Agents; D009241:Ipratropium
keywords: arrhythmias; asthma management; ipratropium bromide; nested case-control design