{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T16:55:54Z","timestamp":1791478554846,"version":"4.3.4"},"reference-count":52,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T00:00:00Z","timestamp":1768348800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T00:00:00Z","timestamp":1768348800000},"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":["178163"],"award-info":[{"award-number":["178163"]}],"id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Addiction"],"published-print":{"date-parts":[[2026,6]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background and aims<\/jats:title>\n                    <jats:p>Canada's drug toxicity crisis has been largely attributed to a volatile fentanyl\u2010dominated unregulated drug supply with increasing reports of fentanyl detected in combination with benzodiazepines, stimulants and xylazine. Although rates of opioid\u2010related harms vary significantly by region, it remains unknown how the composition of the unregulated drug supply differs across Canada. Therefore, we sought to describe trends in Canadian fentanyl\u2010containing drug seizures nationally and compare trends by province\/territory.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>Repeated cross\u2010sectional analysis between February 2020 and December 2024.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting and cases<\/jats:title>\n                    <jats:p>Fentanyl\u2010containing drug samples seized by law enforcement agencies across Canada were analyzed by Health Canada's Drug Analysis Service, with test results made publicly available.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Measurements<\/jats:title>\n                    <jats:p>Counts and crude rates of fentanyl\u2010containing drug seizures, with the population of each province\/territory used to calculate rates per 100\u2009000. We described the number of notable drug classes (e.g. benzodiazepines, stimulants, non\u2010fentanyl opioids, etc.) and chemical substances identified within each drug seizure and used the Cochrane Armitage Test for Trend to look for significant changes over time. All analyses were conducted overall and stratified by province\/territory.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Findings<\/jats:title>\n                    <jats:p>\n                      We identified 71\u2009996 fentanyl\u2010containing drug seizures over the study period, with the quarterly number of seizures increasing by 24.4% (from 2640 in 2020 to 3284 in 2024) across Canada. This varied by province\/territory, with the highest annual rates of fentanyl\u2010containing seizures in 2024 reported in British Columbia (60.4 per 100\u2009000) and Alberta (52.3 per 100\u2009000). Among fentanyl types, we observed statistically significant increases (\n                      <jats:italic>P<\/jats:italic>\n                      \u2009&lt;\u20090.001) in the detection of para\u2010flurofentanyl (0.0% to 46.3%) and methylfentanyl (0.0% to 28.6%). Additionally, there was a notable rise in the annual proportion of seizures in which benzodiazepines (13.4% to 40.2%) or xylazine (1.5% to 18.9%) were detected. Approximately half of all seizures contained fentanyl in combination with at least one other drug class and over 95% contained fentanyl in combination with at least one other chemical substance.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Across Canada from 2020 to 2024, there has been a 24% increase in fentanyl\u2010containing drug seizures in which multiple substances are detected, most notably benzodiazepines, xylazine and potent fentanyl analogues within a single sample.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1111\/add.70314","type":"journal-article","created":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T08:25:17Z","timestamp":1768379117000},"page":"1530-1540","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Trends in fentanyl\u2010containing drug samples seized by law enforcement agencies across Canada"],"prefix":"10.1111","volume":"121","author":[{"given":"Shaleesa","family":"Ledlie","sequence":"first","affiliation":[{"name":"Li Ka Shing Knowledge Institute St. Michael's Hospital  Toronto Canada"},{"name":"Leslie Dan Faculty of Pharmacy University of Toronto  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ria","family":"Garg","sequence":"additional","affiliation":[{"name":"Li Ka Shing Knowledge Institute St. Michael's Hospital  Toronto Canada"},{"name":"Leslie Dan Faculty of Pharmacy University of Toronto  Toronto Canada"},{"name":"ICES  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pamela","family":"Leece","sequence":"additional","affiliation":[{"name":"Public Health Ontario  Toronto Canada"},{"name":"Dalla Lana School of Public Health University of Toronto  Toronto Canada"},{"name":"Department of Family and Community Medicine University of Toronto  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gillian","family":"Kolla","sequence":"additional","affiliation":[{"name":"Faculty of Medicine Memorial University  St. Johns Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5785-8890","authenticated-orcid":false,"given":"Elaine","family":"Hyshka","sequence":"additional","affiliation":[{"name":"School of Public Health University of Alberta  Edmonton Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mina","family":"Tadrous","sequence":"additional","affiliation":[{"name":"Leslie Dan Faculty of Pharmacy University of Toronto  Toronto Canada"},{"name":"ICES  Toronto Canada"},{"name":"Women's College Research Institute  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1468-1965","authenticated-orcid":false,"given":"Tara","family":"Gomes","sequence":"additional","affiliation":[{"name":"Li Ka Shing Knowledge Institute St. Michael's Hospital  Toronto Canada"},{"name":"Leslie Dan Faculty of Pharmacy University of Toronto  Toronto Canada"},{"name":"ICES  Toronto Canada"},{"name":"MAP Centre for Urban Health Solutions, St. Michael's Hospital  Toronto Canada"},{"name":"Institute of Health Policy, Management and Evaluation University of Toronto  Toronto Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,1,14]]},"reference":[{"key":"e_1_2_10_2_1","unstructured":"The Centre for Addiction and Mental Health (CAMH).Opioid Agonist Therapy: A Synthesis of Canadian Guidelines for Treating Opioid Use Disorder. 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