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Updated: May 8, 2026

Microdialysis of Excitatory Amino Acids During EEG Recordings in Freely Moving Rats
Published on: November 8, 2018
Hyperammonemia induced by interaction of valproate and quetiapine
Athar Halaby1, Ramzi Haddad, Wadih J Naja
1Department of Psychiatry, Faculty of Medical Sciences-Lebanese University, Mount Lebanon Hospital, Lebanon. athar3184@hotmail.com.
Introduction:
Hyperammonemia is one of the rare nevertheless serious side effects associated with valproic acid treatment. Two cases of valproic acid induced hyperammonemia are detailed in this article.
Cases:
Case one describes an adult male who developed hyperammonemia after acute exposure to valproic acid as a treatment for his bipolar disorder-manic episode. Case two developed a similar pattern of toxicity but after chronic exposure to valproic acid. Both patients were receiving a combination of valproic acid and quetiapine.
Discussion:
Measurement of the ammonium level should be considered where there is a decreased level of consciousness in patients receiving valproic acid irrespective of the diagnosis and even after a long term exposure. A possible risk of hyperammonemia can result from a combination of valproic acid and quetiapine, however further studies are yet needed to confirm this hypothesis.
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