title: Factor XIII deficiency associated with valproate treatment.
abstract: OBJECTIVE
  We present two children who developed a deficiency of factor XIII with valproate (VPA) treatment. This coagulation disorder has not been described in association with VPA treatment in children, and only very recently in one adult patient.
  
  
  RESULTS
  Both patients showed recurrent epistaxis as major clinical sign of a combination of decreased coagulation parameters (factor XIII deficiency with thrombocytopenia and decreased von Willebrand factor, respectively). A few days after reduction or withdrawal of VPA treatment, clinical symptoms disappeared, and laboratory findings were within normal range.
  
  
  CONCLUSIONS
  VPA is known to influence the synthetic function of the liver and the number and function of megakaryocytes. Therefore an alteration of the factor XIII level by VPA is conceivable. Our case reports suggest that bleeding symptoms during VPA treatment may be caused or aggravated by a decreased factor XIII activity. A determination of factor XIII activity should be considered before surgical procedures during VPA treatment to minimize the risk of (severe) postsurgical bleeding complications.
authors.affiliation: Department of Pediatrics, Mannheim University Hospital, University of Heidelberg, Heidelberg, Germany. martin.teich@kikli.ma.uni-heidelberg.de
authors.forename: Martin
authors.initials: M
authors.lastname: Teich
authors.forename: Elke
authors.initials: E
authors.lastname: Longin
authors.forename: Carl-Erik
authors.initials: CE
authors.lastname: Dempfle
authors.forename: Stephan
authors.initials: S
authors.lastname: König
mesh_terms: D000927:Anticonvulsants / Q000009:adverse effects*; D002648:Child; D004831:Epilepsies, Myoclonic / Q000188:drug therapy*; D004832:Epilepsy, Absence / Q000188:drug therapy; D004829:Epilepsy, Generalized / Q000188:drug therapy*; D004844:Epistaxis / Q000139:chemically induced; D005177:Factor XIII Deficiency / Q000139:chemically induced*; D005260:Female; D006801:Humans; D008297:Male; D014635:Valproic Acid / Q000009:adverse effects*
chemical_list: D000927:Anticonvulsants; D014635:Valproic Acid