title: Confusion, a rather serious adverse drug reaction with valproic acid: a review of the French Pharmacovigilance database.
abstract: BACKGROUND
  Confusion is an adverse drug reaction frequently observed with valproic acid. Some case reports are published in the literature but no systematic study from a sample of patients has been published. We performed this study in order to describe the main characteristics of this adverse drug reaction.
  
  
  METHODS
  Using the French Pharmacovigilance database, we selected the cases of confusion reported since 1985 with valproic acid.
  
  
  RESULTS
  272 cases of confusion were reported with valproic acid: 153 women and 119 men. Confusion mostly occurred during the two first weeks following valproic acid exposure (39.7%). It was "serious" for almost 2/3 of the patients (62.5%) and its outcome favourable in most of the cases (82%). The occurrence of this ADR was more frequent in patients aged between 61 and 80 years.
  
  
  CONCLUSIONS
  This work shows that confusion with valproic acid is a serious, rather frequent but reversible adverse drug reaction. It occurs especially in older patients and during the first two weeks of treatment.
authors.affiliation: Unité de Pharmacoépidémiologie, Université de Toulouse, Faculté de Médecine, and Service de Pharmacologie Clinique, Centre Midi-Pyrénées de Pharmcovigilance, Centre Hospitalier Universitaire de Toulouse, France. guitton@cict.fr
authors.forename: E
authors.initials: E
authors.lastname: Bondon-Guitton
authors.forename: A
authors.initials: A
authors.lastname: Sommet
authors.forename: J L
authors.initials: JL
authors.lastname: Montastruc
mesh_terms: D000293:Adolescent; D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003221:Confusion / Q000139:chemically induced* / Q000453:epidemiology* / Q000401:mortality; D016208:Databases, Factual; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013997:Time Factors; D014635:Valproic Acid / Q000008:administration & dosage / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D014635:Valproic Acid