title: Hyperammonemic Encephalopathy due to Valproic Acid and Topiramate Interaction.
abstract: Valproic acid-induced hyperammonemic encephalopathy is a rare yet serious adverse drug reaction. Medication interactions such a valproic acid and topiramate can precipitate an event. We present the case of a 52-year-old female that presented with acute mental status change and hypersomnolence due to hyperammonemia caused by a valproic acid derivative. The patient improved after withdrawal of the offending medications and treatment with lactulose. Clinicians should remain hypervigilant in monitoring for valproic acid-induced hyperammonemic encephalopathy and risk factors such as polypharmacy.
authors.affiliation: Methodist University Hospital, 1265 Union Avenue Memphis, TN 38104, USA ; Department of Clinical Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Twilla
authors.affiliation: Methodist University Hospital, 1265 Union Avenue Memphis, TN 38104, USA ; Department of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Pierce