{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,29]],"date-time":"2026-05-29T12:48:46Z","timestamp":1780058926112,"version":"3.54.0"},"reference-count":19,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T00:00:00Z","timestamp":1774569600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>We report the case of a 69-year-old Hispanic female with end-stage renal disease (ESRD) on hemodialysis and a complex medical history who presented with acute altered mental status shortly after initiating valacyclovir at a non-renally adjusted dose. The patient was admitted to inpatient services and treated with a presumptive diagnosis of valacyclovir-associated neurotoxicity (VAN). The patient received hemodialysis for three consecutive days, resulting in neurologic improvement. Additional competing causes of altered mental status and encephalopathy were investigated and ruled out over the course of a five-day hospitalization. The patient was subsequently discharged with a diagnosis of VAN. This case underscores the importance of proper renal dose adjustment and medication safety in patients with ESRD to prevent serious, avoidable adverse drug events.<\/jats:p>","DOI":"10.3390\/microorganisms14040755","type":"journal-article","created":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T14:33:33Z","timestamp":1774622013000},"page":"755","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["A\u00a0Case Report of Valacyclovir-Associated Neurotoxicity"],"prefix":"10.3390","volume":"14","author":[{"given":"Kim","family":"Hoang","sequence":"first","affiliation":[{"name":"Irvine Medical Center, University of California, Orange, CA 92868, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8051-7012","authenticated-orcid":false,"given":"Tatiana","family":"Barrera","sequence":"additional","affiliation":[{"name":"School of Medicine, University of California, Irvine, CA 92617, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miki","family":"Watanabe","sequence":"additional","affiliation":[{"name":"School of Medicine, University of California, Irvine, CA 92617, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9032-0387","authenticated-orcid":false,"given":"Herman Joseph","family":"Johannesmeyer","sequence":"additional","affiliation":[{"name":"School of Pharmacy and Pharmaceutical Sciences, University of California, Irvine, CA 92617, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,27]]},"reference":[{"key":"ref_1","unstructured":"Valtrex (valacyclovir) (2026, March 23). Prescribing Information. GlaxoSmithKline, Available online: https:\/\/www.accessdata.fda.gov\/drugsatfda_docs\/label\/2008\/020487s014lbl.pdf."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1135","DOI":"10.1093\/ndt\/gfg119","article-title":"High serum concentrations of the acyclovir main metabolite 9-carboxymethoxymethylguanine in renal failure patients with acyclovir-related neuropsychiatric side effects: An observational study","volume":"18","author":"Diener","year":"2003","journal-title":"Nephro. Dial. Transplant."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"918","DOI":"10.1111\/jcpt.13464","article-title":"Neurotoxicity associated with acyclovir and valacyclovir: A systematic review of cases","volume":"46","year":"2021","journal-title":"J. Clin. Pharm. 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Neurol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"428","DOI":"10.1159\/000188514","article-title":"Avoiding acyclovir neurotoxicity in patients with chronic renal failure undergoing haemodialysis","volume":"69","author":"Almond","year":"1995","journal-title":"Nephron"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1843","DOI":"10.1345\/aph.1L307","article-title":"Cephalosporin-induced neurotoxicity: Clinical manifestations, potential pathogenic mechanisms, and the role of electroencephalographic monitoring","volume":"42","author":"Grill","year":"2008","journal-title":"Ann. Pharmacother."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1557","DOI":"10.1001\/jama.2023.20583","article-title":"Cefepime vs. Piperacillin-Tazobactam in Adults Hospitalized with Acute Infection: The ACORN Randomized Clinical Trial","volume":"330","author":"Qian","year":"2023","journal-title":"JAMA"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"782","DOI":"10.1016\/j.jadohealth.2006.05.005","article-title":"Delirium in an adolescent patient during treatment with cephalexin","volume":"39","author":"Pasila","year":"2006","journal-title":"J. Adolesc. Health"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1038\/clpt.1981.154","article-title":"A method for estimating the probability of adverse drug reactions","volume":"30","author":"Naranjo","year":"1981","journal-title":"Clin. Pharmacol. 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