title: Topiramate enhances the risk of valproate-associated side effects in three children.
abstract: OBJECTIVE
  We present three children with severe therapy-refractory epilepsy who tolerated valproate (VPA) well in various combinations with other antiepileptic drugs (AEDs) but developed typical VPA side effects in combination with topiramate (TPM).
  
  
  METHODS
  The clinical symptoms began with apathy in all three children; two of them also had hypothermia. Furthermore all children had elevated blood ammonia levels, one child in combination with increased liver transaminases and one with thrombocytopenia.
  
  
  RESULTS
  All children recovered completely after discontinuation of VPA or TPM.
  
  
  CONCLUSIONS
  TPM seems likely to enhance the risk of side effects usually attributed to VPA and not described in TPM monotherapy. Our case reports suggest that possible adverse effects of VPA should be given particular attention when VPA is combined with TPM.
authors.affiliation: Children's Hospital, University of Mannheim, Theodor-Kutzer-Ufer, 68167 Mannheim, Germany. elke.longin@kikli.ma.uni-heidelberg.de
authors.forename: Elke
authors.initials: E
authors.lastname: Longin
authors.forename: Martin
authors.initials: M
authors.lastname: Teich
authors.forename: W
authors.initials: W
authors.lastname: Koelfen
authors.forename: Stefan
authors.initials: S
authors.lastname: König
mesh_terms: D000342:Affective Symptoms / Q000139:chemically induced; D000927:Anticonvulsants / Q000009:adverse effects*; D056486:Chemical and Drug Induced Liver Injury; D004359:Drug Therapy, Combination; D004827:Epilepsy / Q000188:drug therapy*; D005260:Female; D005632:Fructose / Q000009:adverse effects* / Q000031:analogs & derivatives; D006801:Humans; D022124:Hyperammonemia / Q000139:chemically induced*; D007035:Hypothermia / Q000139:chemically induced*; D007223:Infant; D008099:Liver / Q000201:enzymology; D008107:Liver Diseases / Q000201:enzymology; D008297:Male; D012307:Risk Factors; D013921:Thrombocytopenia / Q000139:chemically induced*; D000077236:Topiramate; D000637:Transaminases / Q000378:metabolism; D014635:Valproic Acid / Q000009:adverse effects*
chemical_list: D000927:Anticonvulsants; D000077236:Topiramate; D005632:Fructose; D014635:Valproic Acid; D000637:Transaminases