Investigating post-mortem redistribution of drugs in a cohort of suspected unnatural deaths in Cape Town South Africa

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dc.contributor.advisorKirk, Gavin
dc.contributor.advisorHlela, Marie Belle Kathrina Mendoza
dc.contributor.authorClegg, Liza
dc.date.accessioned2025-01-28T09:48:44Z
dc.date.available2025-01-28T09:48:44Z
dc.date.issued2024
dc.date.updated2025-01-28T09:46:16Z
dc.description.abstractIntroduction: The interpretation of post-mortem toxicological analysis results is complex, specifically, due to the phenomenon of post-mortem redistribution (PMR). The later needs to be taken into consideration when determining if, and to what extent a drug contributed to death. Additionally, case specific features also play a role and therefore no specific drug concentration can be deemed ‘fatal'. The accumulation of drugs in specific body areas before and around death creates drug reservoirs, influencing redistribution after death. However, patterns like concentration ratios between cardiac and peripheral blood aid in understanding PMR tendencies of specific drugs. By contributing data to the larger knowledge pool, we can better understand how different drugs behave in the post-mortem seeing, thereby assisting toxicologists and pathologists to come to a rational conclusion regarding the post-mortem toxicological results on a case-by-case basis. Methods: This study is the first of its kind in South Africa, aiming to investigate the extent of PMR of common drugs of use and misuse. To this end, paired admission femoral blood and autopsy femoral and cardiac blood samples were tested on a quantitative LC-MS/MS panel of 31 commonly misused drugs. Results: A total of 109 suspected unnatural cases admitted to the mortuary were included, of which 61 (56%) yielded positive toxicology results. The data was analysed using SPSS Version 28. The most common analytes detected were acetaminophen (n=13; 21.3%), 11-nor-9-carboxy-Δ⁹- tetrahydrocannabinol (THC-COOH) (n=20; 37.8%), amphetamine (n=30; 49.2%), methaqualone (n=33; 54.1%) and methamphetamine (n=33; 54.1%). Males represented the majority of cases in the cohort and the mean age of individuals testing positive was 33 years (SD: 10 years). Cardiac/peripheral (C/P) ratios were calculated and significant pairwise differences with Bonferroni correction were found for amphetamine, methamphetamine and nor-carboxy-tetrahydrocannabinol, corresponding with current literature. Additionally, where the literature was previously lacking data on the PMR of methaqualone, this study suggested that it is less likely to undergo PMR.
dc.identifier.apacitationClegg, L. (2024). <i>Investigating post-mortem redistribution of drugs in a cohort of suspected unnatural deaths in Cape Town South Africa</i>. (). University of Cape Town ,Faculty of Health Sciences ,Department of Pathology. Retrieved from http://hdl.handle.net/11427/40837en_ZA
dc.identifier.chicagocitationClegg, Liza. <i>"Investigating post-mortem redistribution of drugs in a cohort of suspected unnatural deaths in Cape Town South Africa."</i> ., University of Cape Town ,Faculty of Health Sciences ,Department of Pathology, 2024. http://hdl.handle.net/11427/40837en_ZA
dc.identifier.citationClegg, L. 2024. Investigating post-mortem redistribution of drugs in a cohort of suspected unnatural deaths in Cape Town South Africa. . University of Cape Town ,Faculty of Health Sciences ,Department of Pathology. http://hdl.handle.net/11427/40837en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Clegg, Liza AB - Introduction: The interpretation of post-mortem toxicological analysis results is complex, specifically, due to the phenomenon of post-mortem redistribution (PMR). The later needs to be taken into consideration when determining if, and to what extent a drug contributed to death. Additionally, case specific features also play a role and therefore no specific drug concentration can be deemed ‘fatal'. The accumulation of drugs in specific body areas before and around death creates drug reservoirs, influencing redistribution after death. However, patterns like concentration ratios between cardiac and peripheral blood aid in understanding PMR tendencies of specific drugs. By contributing data to the larger knowledge pool, we can better understand how different drugs behave in the post-mortem seeing, thereby assisting toxicologists and pathologists to come to a rational conclusion regarding the post-mortem toxicological results on a case-by-case basis. Methods: This study is the first of its kind in South Africa, aiming to investigate the extent of PMR of common drugs of use and misuse. To this end, paired admission femoral blood and autopsy femoral and cardiac blood samples were tested on a quantitative LC-MS/MS panel of 31 commonly misused drugs. Results: A total of 109 suspected unnatural cases admitted to the mortuary were included, of which 61 (56%) yielded positive toxicology results. The data was analysed using SPSS Version 28. The most common analytes detected were acetaminophen (n=13; 21.3%), 11-nor-9-carboxy-Δ⁹- tetrahydrocannabinol (THC-COOH) (n=20; 37.8%), amphetamine (n=30; 49.2%), methaqualone (n=33; 54.1%) and methamphetamine (n=33; 54.1%). Males represented the majority of cases in the cohort and the mean age of individuals testing positive was 33 years (SD: 10 years). Cardiac/peripheral (C/P) ratios were calculated and significant pairwise differences with Bonferroni correction were found for amphetamine, methamphetamine and nor-carboxy-tetrahydrocannabinol, corresponding with current literature. Additionally, where the literature was previously lacking data on the PMR of methaqualone, this study suggested that it is less likely to undergo PMR. DA - 2024 DB - OpenUCT DP - University of Cape Town KW - Post-mortem KW - Toxicology KW - Pharmacokinetics KW - Redistribution KW - C/P ratio KW - PMR LK - https://open.uct.ac.za PB - University of Cape Town PY - 2024 T1 - Investigating post-mortem redistribution of drugs in a cohort of suspected unnatural deaths in Cape Town South Africa TI - Investigating post-mortem redistribution of drugs in a cohort of suspected unnatural deaths in Cape Town South Africa UR - http://hdl.handle.net/11427/40837 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/40837
dc.identifier.vancouvercitationClegg L. Investigating post-mortem redistribution of drugs in a cohort of suspected unnatural deaths in Cape Town South Africa. []. University of Cape Town ,Faculty of Health Sciences ,Department of Pathology, 2024 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/40837en_ZA
dc.language.rfc3066eng
dc.publisher.departmentDepartment of Pathology
dc.publisher.facultyFaculty of Health Sciences
dc.publisher.institutionUniversity of Cape Town
dc.subjectPost-mortem
dc.subjectToxicology
dc.subjectPharmacokinetics
dc.subjectRedistribution
dc.subjectC/P ratio
dc.subjectPMR
dc.titleInvestigating post-mortem redistribution of drugs in a cohort of suspected unnatural deaths in Cape Town South Africa
dc.typeThesis / Dissertation
dc.type.qualificationlevelMasters
dc.type.qualificationlevelMMed
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