title: Citalopram and cardiac toxicity.
abstract: OBJECTIVE
  Citalopram is a selective serotonin reuptake inhibitor (SSRI) antidepressant that is widely used in clinical practice. Recent data have indicated that high therapeutic citalopram doses may cause electrocardiographic abnormalities, and the regulatory authorities have amended its licenced dosage. The present manuscript reviews the available data concerning citalopram and cardiac toxicity.
  
  
  METHODS
  Published data concerning the cardiac effects of citalopram were ascertained, and clinical data were considered separately between adverse effects arising from therapeutic use versus toxicity in the setting of intentional overdose.
  
  
  RESULTS
  The occurrence of electrocardiographic abnormalities has long been recognised as a complication of acute citalopram overdose; a dose-effect relationship for QT prolongation has been described in a number of large case series, including several cases of torsades de pointes. In contrast, few data indicate the occurrence of QT prolongation and arrhythmia after therapeutic doses, and a dose-effect relationship within the therapeutic range has only recently been established. Citalopram is more likely to cause QT prolongation in patients with metabolic disturbance or pre-existing cardiac disease.
  
  
  CONCLUSIONS
  A dose-effect relationship for QT prolongation exists across a broad range of citalopram doses, such that caution must be exercised when prescribing high doses or if there are co-existent risk factors for QT effects. The available data illustrate how clinical toxicity data may offer an earlier signal of cardiac effects than ascertained from conventional pharmacovigilance methods.
authors.affiliation: Pharmacy Department, York Teaching Hospital NHS Foundation Trust, Wigginton Road, York, YO31 8HE, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Cooke
authors.forename: W S
authors.initials: WS
authors.lastname: Waring
mesh_terms: D000818:Animals; D015283:Citalopram / Q000008:administration & dosage / Q000009:adverse effects* / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D006331:Heart Diseases / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D008133:Long QT Syndrome / Q000139:chemically induced / Q000453:epidemiology; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D015283:Citalopram; D017367:Selective Serotonin Reuptake Inhibitors