title: Fluoroquinolones and the risk of serious arrhythmia: a population-based study.
abstract: BACKGROUND
  Fluoroquinolones have been suspected to cause cardiac arrhythmia but data are lacking, particularly for the individual fluoroquinolones. We assessed the risk of serious arrhythmia, defined as ventricular arrhythmia or sudden/unattended death identified in hospital discharge diagnoses, related to fluoroquinolones as a class as well as for each individual molecule.
  
  
  METHODS
  We used a cohort of patients treated for respiratory conditions from 1 January 1990 to 31 December 2005, identified using the healthcare databases from the province of Quebec (Canada), with follow-up until 31 March 2007. A nested case-control analysis was performed within this cohort, with all cases of serious arrhythmia occurring during follow-up identified from hospitalization records. These cases were matched with up to 20 controls. Conditional logistic regression was used to compute adjusted rate ratios (RRs) of serious arrhythmia associated with fluoroquinolone use.
  
  
  RESULTS
  Within the cohort of 605127 subjects, 1838 cases were identified (incidence rate=4.7/10000 person-years). The rate of serious arrhythmia was elevated with current fluoroquinolone use (RR=1.76; 95% confidence interval [CI], 1.19-2.59), in particular with new current use (RR=2.23; 95% CI, 1.31-3.80). Gatifloxacin use was associated with the highest rate (RR=7.38; 95% CI, 2.30-23.70); moxifloxacin and ciprofloxacin were also associated with elevated rates of serious arrhythmia (RR=3.30; 95% CI, 1.47-7.37 and RR=2.15; 95% CI, 1.34-3.46, respectively).
  
  
  CONCLUSIONS
  The use fluoroquinolones is associated with an elevated risk of serious arrhythmia, with some differences among molecules. Given that the individual fluoroquinolones share various indications, the relative risks of serious arrhythmia could inform the choice of different molecules in high-risk patients.
authors.affiliation: Centre for Clinical Epidemiology, Lady Davis Research Institute, Jewish General Hospital, Montreal, Quebec, Canada.
authors.forename: Francesco
authors.initials: F
authors.lastname: Lapi
authors.forename: Machelle
authors.initials: M
authors.lastname: Wilchesky
authors.forename: Abbas
authors.initials: A
authors.lastname: Kezouh
authors.forename: Jacques I
authors.initials: JI
authors.lastname: Benisty
authors.forename: Pierre
authors.initials: P
authors.lastname: Ernst
authors.forename: Samy
authors.initials: S
authors.lastname: Suissa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D001145:Arrhythmias, Cardiac / Q000139:chemically induced* / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D024841:Fluoroquinolones / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011792:Quebec / Q000453:epidemiology; D012307:Risk Factors
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones