Related Experiment Video
Updated: Apr 25, 2026

Microdialysis of Excitatory Amino Acids During EEG Recordings in Freely Moving Rats
Published on: November 8, 2018
Hyperammonemic Encephalopathy due to Valproic Acid and Topiramate Interaction
Jennifer D Twilla1, Andrew S Pierce2
1Methodist University Hospital, 1265 Union Avenue Memphis, TN 38104, USA ; Department of Clinical Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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.
Related Concept Videos
Hepatic Encephalopathy
Antiepileptic Drugs: GABAergic Pathway Potentiators
The key GABA pathway potentiators used in epilepsy management are as follows.
Benzodiazepines are a well-known class of drugs used for...
Antiepileptic Drugs: Glutamate Antagonists
Antiepileptic Drugs: Modulators of Neurotransmitter Release Mediated by SV2A Protein
SV2A is a transmembrane glycoprotein located predominantly in the brain, modulating the release of neurotransmitters for neuronal communication. Both levetiracetam and brivaracetam exhibit a high affinity for...
Antiepileptic Drugs: Potassium Channel Activators
Ezogabine has gained approval as an adjunctive treatment...
Drug toxicity: Drug–Drug Interaction

