{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T02:04:49Z","timestamp":1780452289617,"version":"3.54.1"},"reference-count":38,"publisher":"American Association of Psychiatric Pharmacists (AAPP)","issue":"3","license":[{"start":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T00:00:00Z","timestamp":1780272000000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/3.0\/"},{"start":{"date-parts":[[2026,6,1]],"date-time":"2026-06-01T00:00:00Z","timestamp":1780272000000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,6]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Hyperammonemia is an idiosyncratic adverse effect associated with valproic acid (VPA). We report 2 patients with neurocognitive disorder who were prescribed low doses of VPA for neuropsychiatric symptoms associated with neurocognitive disorder, and they presented with changes in behavior. On workup, both patients had elevated ammonia concentrations. The aims of the case report are to highlight the importance of laboratory testing for ammonia concentrations in patients with altered mental status especially in the setting of VPA therapy irrespective of the dosage and to discuss possible mechanisms associated with VPA-induced hyperammonemia.<\/jats:p>","DOI":"10.9740\/mhc.2026.06.163","type":"journal-article","created":{"date-parts":[[2026,6,2]],"date-time":"2026-06-02T01:42:05Z","timestamp":1780364525000},"page":"163-166","source":"Crossref","is-referenced-by-count":0,"title":["Hyperammonemia associated with low doses and concentrations of valproic acid in older adults with neurocognitive disorder"],"prefix":"10.9740","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-1862-7770","authenticated-orcid":true,"given":"Sunni","family":"Coyne","sequence":"first","affiliation":[{"name":"Psychiatry resident, Department of Psychiatry, Allegheny Health Network, Pittsburgh, Pennsylvania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9173-1858","authenticated-orcid":true,"given":"Aparna","family":"Das","sequence":"additional","affiliation":[{"name":"(Corresponding author) Attending psychiatrist, Department of Psychiatry, Emory University School of Medicine, Atlanta, Georgia, aparna.das@emory.edu"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"4719","reference":[{"issue":"3","key":"i2168-9709-16-3-163-b01","series-title":"Gen Hosp Psychiatry","first-page":"290","article-title":"Valproate-induced hyperammonemic encephalopathy: an update on risk factors, clinical correlates and management","volume":"34","author":"Chopra","year":"2012","unstructured":"Chopra A,\nKolla BP,\nMansukhani MP,\nNetzel P,\nFrye MA. Valproate-induced hyperammonemic encephalopathy: an update on risk factors, clinical correlates and management. Gen Hosp Psychiatry. 2012;34(3):290-8. DOI: 10.1016\/j.genhosppsych.2011.12.009"},{"issue":"4","key":"i2168-9709-16-3-163-b02","series-title":"Ment Health Clin","first-page":"243","article-title":"Hyperammonemia in patients receiving valproic acid in the hospital setting: a retrospective review","volume":"11","author":"McMorris","year":"2021","unstructured":"McMorris T,\nChu A,\nVu L,\nBernardini A. Hyperammonemia in patients receiving valproic acid in the hospital setting: a retrospective review. Ment Health Clin. 2021;11(4):243-7. DOI: 10.9740\/mhc.2021.07.243"},{"issue":"4","key":"i2168-9709-16-3-163-b03","series-title":"Psychosomatics","first-page":"415","article-title":"Valproate-induced hyperammonemic encephalopathy in general hospital patients with one or more psychiatric disorders","volume":"58","author":"Lewis","year":"2017","unstructured":"Lewis C,\nTesar GE,\nDale R. Valproate-induced hyperammonemic encephalopathy in general hospital patients with one or more psychiatric disorders. Psychosomatics. 2017;58(4):415-20. DOI: 10.1016\/j.psym.2017.02.003"},{"issue":"3","key":"i2168-9709-16-3-163-b04","series-title":"J Clin Psychopharmacol","first-page":"283","article-title":"Valproic acid-associated hyperammonemia: a systematic review","volume":"43","author":"Wong","year":"2023","unstructured":"Wong YJ,\nFan J,\nWan A,\nMihic T,\nGnyra M. Valproic acid-associated hyperammonemia: a systematic review. J Clin Psychopharmacol. 2023;43(3):283-94. 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Available from: https:\/\/www.ncbi.nlm.nih.gov\/sites\/books\/NBK557504\/"},{"issue":"2","key":"i2168-9709-16-3-163-b09","series-title":"Clin Pharmacol Ther","first-page":"239","article-title":"A method for estimating the probability of adverse drug reactions","volume":"30","author":"Naranjo","year":"1981","unstructured":"Naranjo CA,\nBusto U,\nSellers EM,\nSandor P,\nRuiz I,\nRoberts EA, et al. A method for estimating the probability of adverse drug reactions. Clin Pharmacol Ther. 1981;30(2):239-45. DOI: 10.1038\/clpt.1981.154"},{"issue":"1","key":"i2168-9709-16-3-163-b10","series-title":"J Nat Sci Med","first-page":"1","article-title":"A pathophysiological mechanism for valproate-induced hyperammonemia","volume":"6","author":"Rissardo","year":"2023","unstructured":"Rissardo JP,\nCaprara AL. A pathophysiological mechanism for valproate-induced hyperammonemia. J Nat Sci Med. 2023;6(1):1-2. 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Fulminant onset of valproate-associated hyperammonemic encephalopathy. Am J Psychiatry. 2019;176(11):900-3. DOI: 10.1176\/appi.ajp.2019"},{"key":"i2168-9709-16-3-163-b14","article-title":"Aphena Pharma Solutions\u2013Tennessee, LLC. Depakote ER","year":"2000","unstructured":"Aphena Pharma Solutions\u2013Tennessee, LLC. Depakote ER. 2000. DailyMed [Internet]. [revised 2014 Mar 28; cited 2025 Nov 16] National Library of Medicine (US). Available from: https:\/\/dailymed.nlm.nih.gov\/dailymed\/drugInfo.cfm?setid=7bc942e3-b976-4b5c-8874-2a1c7dd3d2f1#section-5.10"},{"issue":"2","key":"i2168-9709-16-3-163-b15","series-title":"Psychiatr Ann","first-page":"90","article-title":"Asymptomatic hyperammonemia caused by valproate: how often to check and how to manage","volume":"49","author":"Storch","year":"2019","unstructured":"Storch DD. Asymptomatic hyperammonemia caused by valproate: how often to check and how to manage. Psychiatr Ann. 2019;49(2):90-2. 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