title: Review of toxicity and trends in the use of tiagabine as reported to US poison centers from 2000 to 2012.
abstract: BACKGROUND
  Tiagabine is a novel antiepileptic that acts by increasing synaptic and extracellular gamma-aminobutyric acid concentrations. Information concerning overdose of tiagabine is limited. After introduction, an increasing number of off-label uses suggested that tiagabine use would increase. However in 2005 and 2008, warnings from the Food and Drug Administration (FDA) were issued on the risk of seizures in non-epileptic and increased suicide ideation. We evaluated the temporal trends associated with these two warnings as well as clinical outcomes from tiagabine overdose.
  
  
  METHODS
  A retrospective review of all single substance tiagabine exposures in National Poison Data System (NPDS) from 2000 to 2012.
  
  
  RESULTS
  A total of 2147 patients had ingested tiagabine, with a mean of 165 year(-1). This was disproportionally distributed, with a steep rise leading up to 2004 (max 559 year(-1)) and then a significant decline (p < 0.05) between 2005 and 2006. The number of cases reported to NPDS mirrored the sales of tiagabine. Clinical effects were predominantly neurological, with the most commonly reported effects being drowsiness (27%), agitation (19%), confusion (12%), seizures (11%), and tachycardia (10%). In all, 758 patients (35%) showed a major or moderate medical outcome, with no deaths reported. A disproportionate share of the major outcomes was in the suicide attempt group (73%). The majority of patients (75%) were treated in a health-care facility (HCF).
  
  
  CONCLUSIONS
  The HCF usage is likely due to high rate of symptomatic patients (59%) and the large proportion of suicide attempt cases. The frequency of tiagabine cases in NPDS mirrored pharmaceutical sales, with steep declines temporally related to the 2005 FDA warning.
authors.affiliation: Central Ohio Poison Center, Nationwide Children's Hospital, Columbus, OH, USA Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA haspiller5@gmail.com.
authors.forename: H A
authors.initials: HA
authors.lastname: Spiller
authors.affiliation: Central Ohio Poison Center, Nationwide Children's Hospital, Columbus, OH, USA.
authors.forename: D
authors.initials: D
authors.lastname: Wiles
authors.affiliation: Central Ohio Poison Center, Nationwide Children's Hospital, Columbus, OH, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Russell
authors.affiliation: Central Ohio Poison Center, Nationwide Children's Hospital, Columbus, OH, USA Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Casavant
mesh_terms: D000927:Anticonvulsants / Q000506:poisoning / Q000633:toxicity*; D062787:Drug Overdose; D006801:Humans; D009557:Nipecotic Acids / Q000506:poisoning / Q000633:toxicity*; D011039:Poison Control Centers / Q000706:statistics & numerical data*; D013406:Suicide, Attempted; D000078308:Tiagabine; D014481:United States / Q000453:epidemiology
chemical_list: D000927:Anticonvulsants; D009557:Nipecotic Acids; D000078308:Tiagabine
keywords: FDA warning; Tiagabine; toxicity