{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T12:40:15Z","timestamp":1792586415180,"version":"4.5.0"},"reference-count":22,"publisher":"Springer Science and Business Media LLC","issue":"2","license":[{"start":{"date-parts":[[2025,10,18]],"date-time":"2025-10-18T00:00:00Z","timestamp":1760745600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,10,18]],"date-time":"2025-10-18T00:00:00Z","timestamp":1760745600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"name":"Universit\u00e4tsklinikum Freiburg"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Int J Legal Med"],"published-print":{"date-parts":[[2026,3]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>\n                      The presence of 2-benzylbenzimidazole-derived opioids (nitazenes) in the drug market is steadily increasing. These often highly potent synthetic opioids can cause severe, potentially fatal effects. This case report presents a fatal intoxication following the vaping of the novel synthetic opioid\n                      <jats:italic>N<\/jats:italic>\n                      -pyrrolidino protonitazene (protonitazepyne), detected in serum obtained 10\u00a0h postmortem and in multiple specimens collected at autopsy three days after death.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      Concentrations of\n                      <jats:italic>N<\/jats:italic>\n                      -pyrrolidino protonitazene in postmortem serum, heart blood, femoral blood, liver, bile, and stomach contents were determined using liquid chromatography\u2013tandem mass spectrometry (LC\u2013MS\/MS) with a standard addition approach. Urine and serum were additionally analyzed via LC\u2013MS\/MS using external matrix calibration.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results and discussion<\/jats:title>\n                    <jats:p>\n                      <jats:italic>N<\/jats:italic>\n                      -Pyrrolidino protonitazene was detected at 3.8 ng\/mL in postmortem serum, 1.7 ng\/mL in heart blood, approx. 0.52 ng\/mL in femoral blood, 0.34 ng\/g in liver, 32.3 ng\/mL in bile, and 19.7 ng\/mL in stomach contents. Urine contained 8.8 ng\/mL. Additional findings in postmortem serum included pregabalin (7.2\u00a0\u00b5g\/mL), sertraline (66 ng\/mL), naloxone (10.2 ng\/mL), mitragynine (11.5 ng\/mL), and traces of quetiapine. These co-ingestants did likely not account for the fatal outcome. With an estimated in vitro potency approximately 25-fold greater than fentanyl, even low doses of N-pyrrolidino protonitazene can be lethal. Elevated heart-to-femoral blood ratios indicate postmortem redistribution, while declining levels over time may indicate compound instability.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>\n                      Due to its high potency,\n                      <jats:italic>N<\/jats:italic>\n                      -pyrrolidino protonitazene is considered the primary cause of death. Accordingly, a toxicological significance score of 3 is assigned, underscoring the potential public health risk posed by this novel synthetic opioid.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s00414-025-03618-8","type":"journal-article","created":{"date-parts":[[2025,10,18]],"date-time":"2025-10-18T02:42:34Z","timestamp":1760755354000},"page":"763-768","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["A case of fatal intoxication with the novel synthetic opioid N-pyrrolidino protonitazene"],"prefix":"10.1007","volume":"140","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-0888-8036","authenticated-orcid":false,"given":"Sophia","family":"Wrbas","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tom R.","family":"Sundermann","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1883-2804","authenticated-orcid":false,"given":"Volker","family":"Auw\u00e4rter","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4190-5469","authenticated-orcid":false,"given":"Laura M.","family":"Huppertz","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2025,10,18]]},"reference":[{"key":"3618_CR1","volume-title":"European drug report 2023","author":"European Monitoring Centre for Drugs and Drug Addiction","year":"2023","unstructured":"European Monitoring Centre for Drugs and Drug Addiction (2023) European drug report 2023. 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