Hyperammonemic encephalopathy induced by valproic acid

BMJ Case Rep. 2024 Feb 13;17(2):e257144. doi: 10.1136/bcr-2023-257144.

Abstract

Valproate (VPA) is broad-spectrum antiepileptic drug. Several adverse reactions including hepatotoxicity, fetal risk and pancreatitis are well known and labelled as boxed warnings in the USA. One adverse reaction that is less well known but clinically significant for its severe morbidity is hyperammonemic encephalopathy. We present a case of woman with hyperammonemic encephalopathy following the initiation of VPA therapy; she had a favourable outcome with discontinuation of the drug and prompt treatment with lactulose and L-carnitine.

Keywords: Drugs: CNS (not psychiatric); Healthcare improvement and patient safety; Psychiatry (drugs and medicines); Safety; Unwanted effects / adverse reactions.

Publication types

  • Case Reports

MeSH terms

  • Anticonvulsants / adverse effects
  • Brain Diseases* / chemically induced
  • Brain Diseases* / drug therapy
  • Female
  • Humans
  • Hyperammonemia* / drug therapy
  • Neurotoxicity Syndromes* / drug therapy
  • Pregnancy
  • Valproic Acid / adverse effects

Substances

  • Valproic Acid
  • Anticonvulsants