{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T13:45:45Z","timestamp":1792590345692,"version":"4.5.0"},"reference-count":25,"publisher":"Oxford University Press (OUP)","issue":"7","license":[{"start":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:00:00Z","timestamp":1782864000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,7,23]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Interpretation of postmortem toxicology results is complicated by postmortem redistribution (PMR), which can alter drug concentrations between tissues and blood (BL). This study evaluates brain (BR) to BL concentration ratios for amphetamine (AMP), methamphetamine (MAMP), cocaine (COC), benzoylecgonine (BE), cocaethylene (CE), and fentanyl (FENT) using postmortem casework data to evaluate the utility of BR tissue as an alternative matrix. BR:BL ratios varied widely across analytes: AMP (2.2\u20135.8), BE (0.2\u20132.1), CE (1.2\u20135.1), COC (0.1\u20135.8), MAMP (2.2\u20137.3), and FENT (1.1\u201324.8). Lipophilic compounds (AMP, CE, COC, MAMP, and FENT) generally exhibited ratios greater than one, consistent with preferential BR partitioning and susceptibility to PMR, whereas the polar metabolite BE showed ratios less than one, reflecting limited BR accumulation. FENT demonstrated the greatest variability, highlighting challenges in interpreting its postmortem concentrations. Correlations between BR and femoral BL concentrations were slightly positive for all analytes, indicating that BR concentrations may not be reliable proxies for BL levels. Evaluation of select antemortem cases and outliers revealed additional influences on BR:BL ratios, including survival time, drug stability, route of administration, and polysubstance use. COC instability and hydrolysis to BE, as well as incomplete drug distribution in rapid deaths, contributed to atypical ratios. Overall, BR:BL ratios are highly analyte dependent and influenced by both pharmacokinetic properties and postmortem factors. While BR tissue may provide useful complementary information when BL is unavailable, it should not be used as a direct substitute for BL in toxicological interpretation. These findings underscore the need for further research to expand BR:BL datasets across drug classes.<\/jats:p>","DOI":"10.1093\/jat\/bkag068","type":"journal-article","created":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T12:07:35Z","timestamp":1784722055000},"source":"Crossref","is-referenced-by-count":1,"title":["Occipital lobe to femoral blood ratios of amphetamine, methamphetamine, cocaine, benzoylecgonine, cocaethylene, and fentanyl in postmortem cases"],"prefix":"10.1093","volume":"50","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-8324-5807","authenticated-orcid":false,"given":"Grayce","family":"Behnke","sequence":"first","affiliation":[{"name":"Harris County Institute of Forensic Sciences Forensic Toxicology, , Houston, TX 77954,","place":["United States"]},{"name":"Oklahoma State University School of Forensic Sciences, , Stillwater, OK 74078,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Teresa R","family":"Gray","sequence":"additional","affiliation":[{"name":"Harris County Institute of Forensic Sciences Forensic Toxicology, , Houston, TX 77954,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,7,22]]},"reference":[{"key":"2026080410021422400_bkag068-B1","volume-title":"Principles of Forensic Toxicology","author":"Kerrigan","year":"2020"},{"key":"2026080410021422400_bkag068-B2","doi-asserted-by":"publisher","first-page":"112699","DOI":"10.1016\/j.forsciint.2025.112699","article-title":"50 Years of postmortem redistribution research: what have we learned?","volume":"378","author":"Borra","year":"2026","journal-title":"Forensic Sci Int"},{"key":"2026080410021422400_bkag068-B3","doi-asserted-by":"publisher","first-page":"1483","DOI":"10.1007\/s12024-023-00709-z","article-title":"Postmortem redistribution of drugs: a literature review","volume":"20","author":"Abdelaal","year":"2024","journal-title":"Forensic Sci Med Pathol"},{"key":"2026080410021422400_bkag068-B4","first-page":"211","volume-title":"Encyclopedia of Forensic and Legal Medicine","author":"Pounder","year":".","edition":"1st edn."},{"key":"2026080410021422400_bkag068-B5","doi-asserted-by":"publisher","first-page":"137","DOI":"10.1093\/jat\/bku139","article-title":"Brain tissue: a viable postmortem toxicological specimen","volume":"39","author":"Rohrig","year":"2015","journal-title":"J Anal Toxicol"},{"key":"2026080410021422400_bkag068-B6","doi-asserted-by":"publisher","first-page":"53","DOI":"10.1093\/jat\/bkaa048","article-title":"Postmortem brain-blood ratios of codeine, fentanyl, oxycodone and tramadol","volume":"45","author":"Nedahl","year":"2021","journal-title":"J Anal Toxicol"},{"key":"2026080410021422400_bkag068-B7","doi-asserted-by":"publisher","first-page":"378","DOI":"10.1093\/jat\/bky110","article-title":"Postmortem brain\u2013blood ratios of amphetamine, cocaine, ephedrine, MDMA and methylphenidate","volume":"43","author":"Nedahl","year":"2019","journal-title":"J Anal Toxicol"},{"key":"2026080410021422400_bkag068-B8","doi-asserted-by":"publisher","first-page":"209","DOI":"10.1093\/jat\/bkaf017","article-title":"Brain concentrations and brain\u2013blood ratios of amitriptyline and nortriptyline in forensic postmortem cases","volume":"49","author":"MZ van der","year":"2025","journal-title":"J Anal Toxicol"},{"key":"2026080410021422400_bkag068-B9","doi-asserted-by":"publisher","first-page":"388","DOI":"10.1016\/j.forsciint.2019.06.007","article-title":"Brain-blood ratio of morphine in heroin and morphine autopsy cases","volume":"301","author":"Nedahl","year":"2019","journal-title":"Forensic Sci Int"},{"key":"2026080410021422400_bkag068-B10","doi-asserted-by":"publisher","first-page":"473","DOI":"10.1007\/s00414-021-02502-5","article-title":"Brain\/blood ratios of methadone and ABCB1 polymorphisms in methadone-related deaths","volume":"135","author":"Iwersen-Bergmann","year":"2021","journal-title":"Int J Legal Med"},{"key":"2026080410021422400_bkag068-B11","doi-asserted-by":"publisher","first-page":"39","DOI":"10.1016\/j.forsciint.2016.09.002","article-title":"Nitrobenzodiazepines: postmortem brain and blood reference concentrations","volume":"268","author":"Skov","year":"2016","journal-title":"Forensic Sci Int"},{"key":"2026080410021422400_bkag068-B12","doi-asserted-by":"publisher","first-page":"447","DOI":"10.1309\/AJCP4X5VHFSOERFT","article-title":"Postmortem redistribution of fentanyl in blood","volume":"133","author":"Olson","year":"2010","journal-title":"Am J Clin Pathol"},{"key":"2026080410021422400_bkag068-B13","doi-asserted-by":"publisher","first-page":"bkae093","DOI":"10.1093\/jat\/bkae093","article-title":"Trends in central\/peripheral ratio of fentanyl in Harris County, TX, and Orange County, CA, from 2009 to 2020","volume":"49","author":"Behnke","year":"2025","journal-title":"J Anal Toxicol"},{"key":"2026080410021422400_bkag068-B14","doi-asserted-by":"publisher","first-page":"1557","DOI":"10.1016\/0024-3205(77)90448-9","article-title":"Hydrolysis of cocaine in human plasma by cholinesterase","volume":"20","author":"Stewart","year":"1977","journal-title":"Life Sci"},{"key":"2026080410021422400_bkag068-B15","doi-asserted-by":"publisher","first-page":"266","DOI":"10.1097\/z00007691-200006000-00006","article-title":"Mechanisms of cocaine hydrolysis and metabolism in vitro and in vivo: a clarification","volume":"22","author":"Warner","year":"2000","journal-title":"Ther Drug Monit"},{"key":"2026080410021422400_bkag068-B16","doi-asserted-by":"publisher","first-page":"514","DOI":"10.1093\/jat\/bkae058","article-title":"Brain homogenate stability for stimulant drugs","volume":"48","author":"Behnke","year":"2024","journal-title":"J Anal Toxicol"},{"key":"2026080410021422400_bkag068-B17","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1093\/jat\/bkaf082","article-title":"Expanding fentanyl analog testing to include brain specimens: method validation and homogenate stability assessment","volume":"50","author":"Behnke","year":"2026","journal-title":"J Anal Toxicol"},{"key":"2026080410021422400_bkag068-B18","author":"ANSI\/ASB","year":"2019"},{"key":"2026080410021422400_bkag068-B19","volume-title":"Disposition of Toxic Drugs and Chemicals in Man","author":"Baselt","year":".","edition":"12th edn"},{"key":"2026080410021422400_bkag068-B20","volume-title":"Basic & Clinical Pharmacology, 15e, Book, Section","author":"Katzung","year":"2021"},{"key":"2026080410021422400_bkag068-B21","doi-asserted-by":"publisher","first-page":"771","DOI":"10.3109\/15563650.2010.525514","article-title":"Fentanyl in postmortem forensic toxicology","volume":"48","author":"Palmer","year":"2010","journal-title":"Clin Toxicol (Phila)"},{"key":"2026080410021422400_bkag068-B22","doi-asserted-by":"publisher","first-page":"112551","DOI":"10.1016\/j.forsciint.2025.112551","article-title":"Comparison of pre-mortem and post-mortem blood concentrations of analgesic and sedative drugs in intensive care patients","volume":"375","author":"Lennborn","year":"2025","journal-title":"Forensic Sci Int"},{"key":"2026080410021422400_bkag068-B23","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1093\/jat\/21.1.23","article-title":"Lack of predictable site-dependent differences and time-dependent changes in postmortem concentrations of cocaine, benzoylecgonine, and cocaethylene in humans","volume":"21","author":"Logan","year":"1997","journal-title":"J Anal Toxicol"},{"key":"2026080410021422400_bkag068-B24","doi-asserted-by":"publisher","first-page":"368","DOI":"10.1093\/jat\/bkaa107","article-title":"Postmortem drug redistribution: a compilation of postmortem\/antemortem drug concentration ratios","volume":"45","author":"Mantinieks","year":"2021","journal-title":"J Anal Toxicol"},{"key":"2026080410021422400_bkag068-B25","author":"Blood Specimens: Chemistry and Hematology","year":"."}],"container-title":["Journal of Analytical Toxicology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/jat\/advance-article-pdf\/doi\/10.1093\/jat\/bkag068\/69800881\/bkag068.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jat\/article-pdf\/50\/7\/bkag068\/69800881\/bkag068.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jat\/article-pdf\/50\/7\/bkag068\/69800881\/bkag068.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T14:02:18Z","timestamp":1785852138000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jat\/article\/doi\/10.1093\/jat\/bkag068\/8739961"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7]]},"references-count":25,"journal-issue":{"issue":"7","published-print":{"date-parts":[[2026,7,23]]}},"URL":"https:\/\/doi.org\/10.1093\/jat\/bkag068","relation":{},"ISSN":["1945-2403"],"issn-type":[{"value":"1945-2403","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,7]]},"published":{"date-parts":[[2026,7]]},"article-number":"bkag068"}}