title: Hyperammonemic encephalopathy related to valproate, phenobarbital, and topiramate synergism.
abstract: We present a woman with epilepsy secondary to a lesion in the left frontal lobe. She developed episodes of disorientation and behavioral changes. She was taking valproic acid (1500 mg/day), topiramate (200 mg/day), and phenobarbital (100 mg/day). During an episode, the EEG revealed moderate encephalopathy and ammonia levels were increased (195 μg/dL, reference range: 11-60 μg/dL). Episodes ceased after withdrawal of valproic acid.
authors.affiliation: Department of Neurology, Clinica Universidad de Navarra, Pamplona, Spain. agomezi@unav.es
authors.forename: Asier
authors.initials: A
authors.lastname: Gomez-Ibañez
authors.forename: Elena
authors.initials: E
authors.lastname: Urrestarazu-Bolumburu
authors.forename: Cesar
authors.initials: C
authors.lastname: Viteri-Torres
mesh_terms: D004357:Drug Synergism; D004359:Drug Therapy, Combination; D004827:Epilepsy / Q000188:drug therapy; D005260:Female; D005632:Fructose / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006801:Humans; D022124:Hyperammonemia / Q000139:chemically induced* / Q000175:diagnosis; D008875:Middle Aged; D020258:Neurotoxicity Syndromes / Q000175:diagnosis*; D010634:Phenobarbital / Q000009:adverse effects* / Q000627:therapeutic use; D000077236:Topiramate; D014635:Valproic Acid / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D000077236:Topiramate; D005632:Fructose; D014635:Valproic Acid; D010634:Phenobarbital