{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,3]],"date-time":"2026-08-03T10:47:47Z","timestamp":1785754067730,"version":"3.56.0"},"reference-count":36,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:00:00Z","timestamp":1782864000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:00:00Z","timestamp":1782864000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100000024","name":"Canadian Institutes of Health Research","doi-asserted-by":"publisher","award":["183586"],"award-info":[{"award-number":["183586"]}],"id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000008","name":"Health Canada","doi-asserted-by":"publisher","award":["1718\u2010HQ\u2010000027"],"award-info":[{"award-number":["1718\u2010HQ\u2010000027"]}],"id":[{"id":"10.13039\/501100000008","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000008","name":"Health Canada","doi-asserted-by":"publisher","award":["2324\u2010HQ\u2010000067"],"award-info":[{"award-number":["2324\u2010HQ\u2010000067"]}],"id":[{"id":"10.13039\/501100000008","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100025092","name":"Ministry of Health, Ontario","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100025092","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100011094","name":"Public Health Agency of Canada","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100011094","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100014608","name":"St. Michael\u2019s Hospital Foundation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100014608","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Drug and Alcohol Review"],"published-print":{"date-parts":[[2026,7]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Nitazenes, a highly potent class of synthetic opioids, have emerged in Canadian unregulated drug markets. We report on their presence and composition, along with overdose trends.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Samples were obtained from January 2019 to July 2024 from two drug checking services (Toronto's Drug Checking Service (TDCS) and drug checking partners affiliated with the British Columbia Centre on Substance Use (BCCSU)) and national police seizure data from Health Canada's Drug Analysis Service (HC\u2010DAS). Overdose data were retrieved from the Office of the Chief Coroner for Ontario from January 2019 to December 2022 and included deaths in which a nitazene was present. We conducted Cochran\u2010Armitage test and logistic regression trend analyses to assess trends over time.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Of 668,486 samples, 4074 (0.61%) contained nitazenes: 532 from drug checking services (489 (0.07%) from TDCS; 43 (0.01%) from BCCSU) and 3542 (0.53%) from police seizures (HC\u2010DAS). Twelve unique nitazenes were detected. Common co\u2010occurring drugs included caffeine, benzodiazepine\u2010related drugs and fentanyl and fentanyl\u2010related drugs. Nitazenes were expected in 3 (&lt;\u20091%) of 532 drug checking samples. Of 14,103 samples from TDCS, 886 (6.28%) were associated with an overdose, among which 76 (8.58%) contained nitazenes. Of 8719 opioid deaths in Ontario and 1803 in Toronto, nitazenes were present in 79 (0.91%) and 33 (1.83%), respectively. Significant trends (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001) in nitazene detections and overdoses in Toronto, as well as nitazene detections across Canada, were observed, increasing prior to and peaking in January\u2013March 2022, followed by reductions.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion and Conclusions<\/jats:title>\n                    <jats:p>The presence of nitazenes in Canada requires enhanced overdose prevention responses and drug market monitoring.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/dar.70189","type":"journal-article","created":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T12:56:51Z","timestamp":1782910611000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The Detection of Novel Nitazene\u2010Class Opioids in Unregulated Drug Markets in Canada"],"prefix":"10.1111","volume":"45","author":[{"given":"Emily A.","family":"Gelgoot","sequence":"first","affiliation":[{"name":"Centre on Drug Policy Evaluation, Li Ka Shing Knowledge Institute St. Michael's Hospital  Toronto Canada"},{"name":"Department of Population Medicine University of Guelph  Guelph Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kristy M.","family":"Scarfone","sequence":"additional","affiliation":[{"name":"Centre on Drug Policy Evaluation, Li Ka Shing Knowledge Institute St. Michael's Hospital  Toronto Canada"},{"name":"Leslie Dan Faculty of Pharmacy University of Toronto  Toronto Canada"},{"name":"Clinical Laboratory and Diagnostic Services, Centre for Addiction and Mental Health  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4970-6763","authenticated-orcid":false,"given":"Nazlee","family":"Maghsoudi","sequence":"additional","affiliation":[{"name":"Centre on Drug Policy Evaluation, Li Ka Shing Knowledge Institute St. Michael's Hospital  Toronto Canada"},{"name":"Institute of Health Policy, Management and Evaluation University of Toronto  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karen","family":"McDonald","sequence":"additional","affiliation":[{"name":"Drug Checking Unit, MAP Centre for Urban Health Solutions St. Michael's Hospital  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenqing","family":"Hao","sequence":"additional","affiliation":[{"name":"Drug Checking Unit, MAP Centre for Urban Health Solutions St. Michael's Hospital  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristiana","family":"Stefan","sequence":"additional","affiliation":[{"name":"Clinical Laboratory and Diagnostic Services, Centre for Addiction and Mental Health  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel R.","family":"Beriault","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine St. Michael's Hospital  Toronto Canada"},{"name":"Department of Laboratory Medicine and Pathobiology University of Toronto  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarah R.","family":"Delaney","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine St. Michael's Hospital  Toronto Canada"},{"name":"Department of Laboratory Medicine and Pathobiology University of Toronto  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2470-438X","authenticated-orcid":false,"given":"Lianping","family":"Ti","sequence":"additional","affiliation":[{"name":"British Columbia Centre on Substance Use  Vancouver Canada"},{"name":"Department of Medicine University of British Columbia  Vancouver Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6051-8950","authenticated-orcid":false,"given":"Samuel","family":"Tobias","sequence":"additional","affiliation":[{"name":"British Columbia Centre on Substance Use  Vancouver Canada"},{"name":"School of Population and Public Health University of British Columbia  Vancouver Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeanette M.","family":"Bowles","sequence":"additional","affiliation":[{"name":"British Columbia Centre on Substance Use  Vancouver Canada"},{"name":"Department of Medicine University of British 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