title: Comparative toxicity of citalopram and the newer antidepressants after overdose.
abstract: OBJECTIVE
  To compare the toxicity of citalopram, venlafaxine, mirtazapine, and nefazadone after overdose.
  
  
  METHODS
  Two-year retrospective review of consecutive patients admitted to the toxicology unit of Edinburgh Royal Infirmary. Outcome measure included physiological variables, ECG recordings, peak creatine kinase, development of arrhythmias, seizure, tremor or agitation, and the need for admission to a critical care facility.
  
  
  RESULTS
  A total of 225 patients were studied. Venlafaxine was associated with a significantly higher pulse rate (p < 0.0001) and tremor (p = 0.007) than other antidepressants. Citalopram was associated with a significantly longer QT interval on ECG recording (p < 0.0001) but mean QTc durations were not significantly different between all drugs studied. No arrhythmias were recorded. Only venlafaxine and citalopram caused seizures and were associated with the need for admission to Intensive Care, but there was no significant difference between them.
  
  
  CONCLUSIONS
  Mirtazapine and nefazadone appear safe in overdose and were associated with minimal features of neurological or cardiovascular toxicity. Citalopram is more likely to cause QT prolongation but other features of cardiovascular toxicity were uncommon. Both citalopram and venlafaxine are proconvulsants. Venlafaxine also causes more frequent features of the serotonin syndrome.
authors.affiliation: Scottish Poisons Information Bureau, Royal Infirmary, Little France Crescent, Edinburgh, Scotland, UK. cathy.kelly@luht.scot.nhs.uk
authors.forename: C A
authors.initials: CA
authors.lastname: Kelly
authors.forename: N
authors.initials: N
authors.lastname: Dhaun
authors.forename: W J
authors.initials: WJ
authors.lastname: Laing
authors.forename: F E
authors.initials: FE
authors.lastname: Strachan
authors.forename: A M
authors.initials: AM
authors.lastname: Good
authors.forename: D N
authors.initials: DN
authors.lastname: Bateman
mesh_terms: D000284:Administration, Oral; D000328:Adult; D018687:Antidepressive Agents, Second-Generation / Q000008:administration & dosage / Q000506:poisoning*; D015283:Citalopram / Q000008:administration & dosage / Q000506:poisoning*; D003511:Cyclohexanols / Q000008:administration & dosage / Q000506:poisoning; D062787:Drug Overdose; D005260:Female; D006801:Humans; D008297:Male; D008803:Mianserin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000506:poisoning; D000078785:Mirtazapine; D010879:Piperazines; D011041:Poisoning / Q000209:etiology* / Q000503:physiopathology; D012189:Retrospective Studies; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage / Q000506:poisoning*; D014230:Triazoles / Q000008:administration & dosage / Q000506:poisoning; D000069470:Venlafaxine Hydrochloride
chemical_list: D018687:Antidepressive Agents, Second-Generation; D015283:Citalopram; D003511:Cyclohexanols; D008803:Mianserin; D000078785:Mirtazapine; D010879:Piperazines; D017367:Selective Serotonin Reuptake Inhibitors; D014230:Triazoles; D000069470:Venlafaxine Hydrochloride; C051752:nefazodone