{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,7]],"date-time":"2026-09-07T03:07:53Z","timestamp":1788750473119,"version":"build-2803163510"},"reference-count":15,"publisher":"Wiley","license":[{"start":{"date-parts":[[2026,9,6]],"date-time":"2026-09-06T00:00:00Z","timestamp":1788652800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"},{"start":{"date-parts":[[2026,9,6]],"date-time":"2026-09-06T00:00:00Z","timestamp":1788652800000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Br J Clin Pharmacol"],"abstract":"\n Background<\/jats:title>\n Distribution of illicit counterfeit alprazolam containing the highly potent synthetic opioid\u2010receptor agonist protonitazene recently resulted in a number of severe overdoses in Ireland. We report three cases that presented to our hospital, within 6\u00a0weeks of one another, following ingestion of illicitly\u2010sourced alprazolam. All cases demonstrated clinical and radiological findings consistent with acute toxic leucoencephalopathy.<\/jats:p>\n <\/jats:sec>\n \n Case reports<\/jats:title>\n A 19\u2010year\u2010old male ingested several tablets of counterfeit alprazolam. Magnetic resonance imaging (MRI) demonstrated mild white matter changes consistent with acute toxic leucoencephalopathy. He was extubated after 6\u00a0days and made a full neurological recovery by Day 22. A 30\u2010year\u2010old male suffered an out\u2010of\u2010hospital cardiac arrest following ingestion of illicitly sourced alprazolam. MRI demonstrated extensive white matter changes in a distribution consistent with severe acute toxic leucoencephalopathy. There was no neurological recovery, and he passed away 30\u2009days following presentation. A 36\u2010year\u2010old male was found surrounded by empty packaging of illicitly\u2010sourced alprazolam. He was intubated and subsequent MRI demonstrated near\u2010identical features to that of Case 2. He made no neurological recovery by Day 27 and passed away on Day 45. Analysis by gas chromatography\u2013mass spectrometry identified protonitazene in the recovered tablets of Cases 1 and 2. Case 3 had no tablets available for analysis, though the empty alprazolam packaging was identical to that seen in Cases 1 and 2.<\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n These cases describe a trio of local protonitazene poisonings that were associated with the development of acute toxic leucoencephalopathy. Prognosis was poor but variable, with a correlation between radiological severity and neuroprognostication.<\/jats:p>\n <\/jats:sec>","DOI":"10.1002\/bcp.70817","type":"journal-article","created":{"date-parts":[[2026,9,7]],"date-time":"2026-09-07T02:25:13Z","timestamp":1788747913000},"source":"Crossref","is-referenced-by-count":0,"title":["Acute toxic leucoencephalopathy following protonitazene ingestion"],"prefix":"10.1002","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-1105-571X","authenticated-orcid":false,"given":"Ruadhan","family":"O'Laoi","sequence":"first","affiliation":[{"name":"Department of Pharmacology and Therapeutics, School of Medicine, Trinity Centre for Health Sciences St. James Hospital Dublin Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Holly","family":"Acton","sequence":"additional","affiliation":[{"name":"Department of Radiology St James' Hospital Dublin Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pierce","family":"Kavanagh","sequence":"additional","affiliation":[{"name":"Department of Pharmacology and Therapeutics, School of Medicine, Trinity Centre for Health Sciences St. James Hospital Dublin Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isabelle","family":"Hunt","sequence":"additional","affiliation":[{"name":"Department of Neurology, School of Medicine, Trinity Centre for Health Sciences St. James Hospital Dublin Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Niall","family":"Sheehy","sequence":"additional","affiliation":[{"name":"Department of Radiology St James' Hospital Dublin Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cormac","family":"Kennedy","sequence":"additional","affiliation":[{"name":"Department of Pharmacology and Therapeutics, School of Medicine, Trinity Centre for Health Sciences St. James Hospital Dublin Ireland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,9,6]]},"reference":[{"key":"e_1_2_6_2_1","doi-asserted-by":"publisher","DOI":"10.1111\/bph.70230"},{"key":"e_1_2_6_3_1","unstructured":"United Nations Office on Drugs and Crime.World Drug Report 2024.2024.https:\/\/www.unodc.org\/unodc\/en\/data-and-analysis\/world-drug-report-2024.html[Accessed 20 Jul. 2024]."},{"key":"e_1_2_6_4_1","unstructured":"European Monitoring Centre for Drugs and Drug Addiction.European Drug Report 2023: Trends and Developments.2023.https:\/\/www.emcdda.europa.eu\/publications\/european-drug-report\/2023_en"},{"key":"e_1_2_6_5_1","doi-asserted-by":"publisher","DOI":"10.1002\/dta.3707"},{"key":"e_1_2_6_6_1","unstructured":"Health Service Executive (HSE).Risk Communication\u2014Monitoring Emerging Overdose Situation [Internet]. 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Licence: CC BY\u2010NC\u2010SA 3.0 IGO.2023."},{"key":"e_1_2_6_11_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.2042\u20107158.1966.tb07782.x"},{"key":"e_1_2_6_12_1","doi-asserted-by":"publisher","DOI":"10.1021\/acschemneuro.1c00037"},{"key":"e_1_2_6_13_1","doi-asserted-by":"publisher","DOI":"10.1111\/dar.13998"},{"key":"e_1_2_6_14_1","doi-asserted-by":"publisher","DOI":"10.1080\/15563650.2024.2383692"},{"key":"e_1_2_6_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jns.2022.120420"},{"key":"e_1_2_6_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/S2215\u20100366(19)30218\u20104"}],"container-title":["British Journal of Clinical Pharmacology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/bpspubs.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/bcp.70817","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/bpspubs.onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/bcp.70817","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/bpspubs.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/bcp.70817","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,7]],"date-time":"2026-09-07T02:25:15Z","timestamp":1788747915000},"score":1,"resource":{"primary":{"URL":"https:\/\/bpspubs.onlinelibrary.wiley.com\/doi\/10.1002\/bcp.70817"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,6]]},"references-count":15,"alternative-id":["10.1002\/bcp.70817"],"URL":"https:\/\/doi.org\/10.1002\/bcp.70817","archive":["Portico"],"relation":{},"ISSN":["0306-5251","1365-2125"],"issn-type":[{"value":"0306-5251","type":"print"},{"value":"1365-2125","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,6]]},"article-number":"bcp.70817"}}