Comparative analysis of post-mortem drug concentrations in cerebrospinal fluid and blood

This study aimed to compare the concentration of various xenobiotics in both cerebrospinal fluid (CSF) and blood. We examined 175 autopsy cases covering a wide range of ages, causes of death, and drug ingestion histories, with cerebrospinal fluid and blood samples available for toxicological testing. Analytes studied included opioids, benzodiazepines, antidepressants, antipsychotics, and illicit substances such as cannabinoids, stimulants and new psychoactive substances, including synthetic cathinones and synthetic cannabinoids. We found that concentrations in CSF were generally lower than in blood. A significant correlation was observed between drug concentrations in CSF and blood for many analytes (p < 0.05). However, the strength and direction of the correlation varied considerably depending on the physicochemical properties of the drugs, suggesting that a 'one size fits all' model may not be applicable. The results indicate that cerebrospinal fluid (CSF) can be used to detect a variety of xenobiotics, particularly amphetamines, synthetic cathinones and synthetic cannabinoids, in cases where conventional biological materials are not available. Additionally, using the results obtained in the future can lead to a better understanding of pharmacokinetic processes and the effect of post-mortem redistribution. Further research is needed to refine our understanding of these relationships.