title: Valproic acid-induced hyperammonemia: a case report.
abstract: The authors present a case of a patient treated with valproic acid for seizure disorder who presented with acute mental status changes consistent with encephalopathy. Notably, her serum ammonia level was 3 times the upper limit of normal, despite an only mildly elevated aspartate aminotransferase and normal bilirubin. Her serum valproic acid level was in the therapeutic range. Her symptoms resolved with discontinuation of valproic acid and supportive care. The authors review the possible mechanisms of valproic acid-associated hyperammonemia with encephalopathy and propose clinical practice modifications to minimize the incidence of this adverse reaction to this generally well-tolerated and clinically important psychotropic medication.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, University of California, Davis Medical Center, Sacramento, CA 95817, USA.
authors.forename: Mariposa
authors.initials: M
authors.lastname: McCall
authors.forename: James A
authors.initials: JA
authors.lastname: Bourgeois
mesh_terms: D000641:Ammonia / Q000097:blood; D000927:Anticonvulsants / Q000009:adverse effects* / Q000493:pharmacokinetics / Q000627:therapeutic use; D001806:Blood Urea Nitrogen; D003244:Consciousness Disorders / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis; D003937:Diagnosis, Differential; D004359:Drug Therapy, Combination; D004834:Epilepsy, Post-Traumatic / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006501:Hepatic Encephalopathy / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis; D006801:Humans; D022124:Hyperammonemia / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis; D008111:Liver Function Tests; D008609:Mental Status Schedule; D008875:Middle Aged; D014635:Valproic Acid / Q000009:adverse effects* / Q000493:pharmacokinetics / Q000627:therapeutic use
chemical_list: D000927:Anticonvulsants; D014635:Valproic Acid; D000641:Ammonia