title: In-hospital cardiac arrest is associated with use of non-antiarrhythmic QTc-prolonging drugs.
abstract: OBJECTIVE
  QTc interval-prolonging drugs have been linked to cardiac arrhythmias, cardiac arrest and sudden death. In this study we aimed to quantify the risk of cardiac arrest associated with the use of non-antiarrhythmic QTc-prolonging drugs in an academic hospital setting.
  
  
  METHODS
  We performed a case-control study in which patients, for whom intervention of the advanced life support resuscitation team was requested for cardiac arrest between 1995 and 2003 in the Academic Medical Centre, Amsterdam, were compared with controls regarding current use of non-antiarrhythmic QTc-prolonging drugs. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression, adjusting for potential confounding factors.
  
  
  RESULTS
  A statistically significant increased risk of cardiac arrest (OR 2.1, 95% CI 1.2, 3.5) was observed in patients who received QTc-prolonging drugs (42/140). The risk was more pronounced in patients receiving doses > 1 defined daily dose (OR 2.5, 95% CI 1.1, 5.9), patients taking > 1 QTc-prolonging drug simultaneously (OR 4.8, 95% CI 1.6, 14) and patients taking pharmacokinetic interacting drugs concomitantly (OR 4.0, 95% CI 1.2, 13).
  
  
  CONCLUSIONS
  Use of non-antiarrhythmic QTc-prolonging drugs in hospitalized patients with several underlying disease is associated with an increased risk of cardiac arrest. The effect is dose related and pharmacokinetic drug-drug interactions increase the risk substantially. Physicians caring for inpatients should be made aware of the fact that these non-antiarrhythmic drugs may be hazardous, so that potential risks can be weighed against treatment benefits and additional cardiac surveillance can be requested, if necessary.
authors.affiliation: Utrecht Institute for Pharmaceutical Sciences (UIPS), Department of Pharmacoepidemiology and Pharmacotherapy, Utrecht, The Netherlands. m.l.debruin@pharm.uu.nl
authors.forename: Marie L
authors.initials: ML
authors.lastname: De Bruin
authors.forename: Pim N J
authors.initials: PN
authors.lastname: Langendijk
authors.forename: Richard P
authors.initials: RP
authors.lastname: Koopmans
authors.forename: Arthur A M
authors.initials: AA
authors.lastname: Wilde
authors.forename: Hubert G M
authors.initials: HG
authors.lastname: Leufkens
authors.forename: Arno W
authors.initials: AW
authors.lastname: Hoes
mesh_terms: D000368:Aged; D000889:Anti-Arrhythmia Agents; D016887:Cardiopulmonary Resuscitation; D016022:Case-Control Studies; D005260:Female; D006323:Heart Arrest / Q000139:chemically induced*; D006760:Hospitalization; D006801:Humans; D008133:Long QT Syndrome / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents