Postmortem redistribution of methamphetamine and amphetamine in blood specimens from various blood vessels and in the specimens from pericardial fluid, bile, stomach contents and various solid tissues collected from a human cadaver

Challenges and insights: Methamphetamine analysis in post-mortem putrefied human tissues in a hot climate

Background

The production and distribution of methamphetamine (meth) is often associated with illegal and clandestine laboratories, posing significant challenges for law enforcement and public health efforts. Global concern is growing over meth-related fatalities, as its high potential for abuse and detrimental impact on health make it an important issue in the realm of substance abuse and addiction. This concern has notably increased in Saudi Arabia, where the hot climate adds complexity to the analysis due to challenges posed by putrefaction. There is still an urgent need to enhance the screening capabilities of many toxicology laboratories to determine the cause of death, whether it be due to drug use or natural causes.

Aim

This research aimed to investigate meth concentrations in post-mortem putrefied human solid tissues in a hot climate and comparing meth metabolite concentrations in cases where signs of putrefaction were observed versus those with no signs of putrefaction. The objective is to assist criminal investigations by analyzing meth and its metabolite concentrations.

Methods

This retrospective cohort study involved postmortem samples from human subjects during autopsies conducted between 2016 and 2022. It focused on analyzing meth and its metabolite concentrations using LC-MS/MS analysis. Data on demographics, medical history, age, location, putrefaction, and other drug use were retrieved from medical records.

Results

Out of the 27 reported samples of meth and its metabolite amphetamine in both putrefied and non-putrefied biological fluids and tissues, only 8 (30%) exhibited signs of putrefaction between 2016 and 2022. Despite decomposition, detectable concentrations of meth and amphetamine were sufficient to determine the cause of death and the source of amphetamines.

Conclusion

This study found no significant difference in concentrations between putrefied and non-putrefied cases, underscoring the importance of multiple sample testing during autopsy for accurate interpretation. Each case is unique and must be considered individually.

Postmortem redistribution of amphetamines and benzodiazepines in humans: Important variables that might be influencing the central blood / peripheral blood ratio

INTRODUCTION

The primary objective of postmortem forensic toxicology is to determine if toxicological substances detected in bodily material of victims have contributed to the death of the victim. Interpretation of postmortem drug concentrations is hindered by the fact that time and site dependent variations in postmortem drug concentrations occur, as a result of postmortem redistribution (PMR). An often-used marker for the occurrence of PMR, is the cardiac blood concentration/peripheral blood concentration ratio (C/P ratio) of a drug. In this study, we investigated the relationship between 13 variables and the C/P ratios of amphetamines and benzodiazepines.

METHOD

Toxicological results of all postmortem cases that were positive for amphetamines (amphetamine, MDMA, MDA) and/or benzodiazepines (diazepam, desmethyldiazepam, temazepam, oxazepam, midazolam, α-hydroxymidazolam) investigated by the Netherlands Forensic Institute between January 1 2010 and July 31 2020 were reviewed. A total of 112 amphetamine positive cases (224 paired specimen) and 179 benzodiazepine positive cases (358 paired specimen) were selected. The C/P ratios were determined for all selected cases. Ratios were compared between subgroups by performing either a Mann-Whitney U test or a Kruskal-Wallis test followed by post-hoc Mann-Whitney U test.

RESULTS

After dividing cases in quartiles based on their amphetamine concentration in femoral blood, the amphetamine C/P ratio was significantly lower in cases with a high amphetamine concentration (quartile 4) compared to cases with a low amphetamine concentration (quartiles 1 and 2) with median C/P ratios of 1.6, 2.4 and 2.2, respectively (p-value<0.001 and p-value=0.001, respectively). The MDA C/P ratio was significantly higher in cases where trauma was the cause of death compared to cases where intoxication was the cause of death with median C/P ratios of 3.3 and 1.6, respectively (p-value<0.001). The MDA C/P ratio was also significantly lower in cases where resuscitation was attempted compared to cases where no resuscitation was attempted with median C/P ratios of 1.6 and 2.4, respectively (p-value=0.003). However, a significant dependency between the variables cause of death and attempted resuscitation was observed. No significant differences in benzodiazepine C/P ratios were observed between subgroups of any of the investigated variables. However, the low p-value of BMI suggests a potential difference in midazolam C/P ratio between BMI subgroups (p-value=0.027).

CONCLUSION

When interpreting postmortem toxicological results, it might prove useful to take the above-mentioned variables into account.

The standard addition method and its validation in forensic toxicology

Purpose

In the quantitative forensic toxicological analyses using instruments, major methods to be employed are conventional matrix-matched calibration method (MMCM). However, nowadays, the needs for using the standard addition methods (SAM) are increasing. In spite of this situation, there are no reports of the guidelines for the validations of SAM. In this review, the principle, how to perform it, advantages, disadvantages, reported application data, and the details of validation procedures for the SAM are described.

Methods

Various databases such as SciFinder, Google and Google Scholar were utilized to collect relevant reports referring to the SAM. The long experiences of our research group on the SAM were also included in this review.

Results

Although the experimental procedures for the SAM are much more laborious than those of the MMCM, the SAM is essential to quantify target xenobiotic(s) in special matrices such as human solid tissues or biles, which remarkably interfere with the usual quantitative analyses. The validation methods for the SAM have been also proposed for the cases in the absence of the blank matrices.

Conclusions

To our knowledge, this is the first presentation of detailed SAM procedure and its validation, which will facilitate the use of the SAM in forensic toxicology. Especially for its validation, new simple methods have been proposed.

Methamphetamine-related postmortem cases in Jeddah, Saudi Arabia

A more than 500% increase in the number of deaths involving methamphetamine occurred between 2016 and 2018 in Jeddah, Saudi Arabia. As such, this report employed a validated liquid chromatography tandem mass spectrometry method to quantify methamphetamine and its metabolites in bodily fluids from 47 postmortem cases in which methamphetamine was involved. The mean age of the deceased was 33 years old (median: 30, range: 16-63), and 94% were male. Methamphetamine was co-ingested with another drug in 32 of the cases (68%); however, the deaths were only due to the combined toxicity of methamphetamine and another drug in 15 of the cases (32%). Of note, 13 of these deaths (28% of all deaths) involved heroin. When methamphetamine was the sole cause of death (32% of the studied cases), the median concentrations of methamphetamine and amphetamine were 527 and 128 ng/mL. When methamphetamine was combined toxicity with another drug, the median concentrations of methamphetamine and amphetamine decreased to 161 and 53 ng/mL. When deaths were unrelated to methamphetamine, the median concentrations of methamphetamine and amphetamine were 130 and 44 ng/mL, respectively. The highest median methamphetamine concentration was found in urine (5281 ng/mL), followed by stomach contents (878 ng/mL), bile (762 ng/mL), vitreous humor (3 ng/mL), and blood (208 ng/mL). Almost 40% of the studied cases involved violence, 61% were accidental, 21% were suicides, 17% were homicides, and 2% were natural deaths. Methamphetamine is highly addictive. Increases in deaths have been seen in various countries. More awareness, education and treatment programs are required to reduce the likelihood of addiction, crimes, suicide, and other fatalities resulting from methamphetamine abuse.

Postmortem distribution/redistribution of buformin in body fluids and solid tissues in an autopsy case using liquid chromatography-tandem mass spectrometry with QuEChERS extraction method

An autopsy for a suicidal case of a male in his 40s, who had died of poisoning due to ingestion of a large amount of buformin, was performed at our department. Buformin is biganide class agent used for patients of diabetes mellitus, which can occasionally cause severe lactic acidosis. The autopsy was performed about 10 days after his death, and the direct cause of his death was judged as asphyxia due to the aspiration of stomach contents into the airway. The nine body fluids and eight solid tissues specimens were dealt with for investigating postmortem distribution/redistribution of buformin in a whole body; femoral vein blood, right and left heart blood, pericardial fluid, urine, bile, stomach contents, small intestine contents, cerebrospinal fluid, the brain, lung, heart muscle, liver, spleen, kidney and skeletal muscle were examined. For extracting buformin from specimens, a modified QuEChERS method including dispersive solid-phase extraction was employed, followed by the analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS). Buformin in various kinds of human matrices were quantified by the standard addition method in this study, which can overcome the matrix effects and recovery rates without use of blank human matrices. All concentrations of buformin in specimens examined in this case were extremely higher than those of previously reported poisoning cases. The concentrations of buformin in left and right heart blood and femoral vein blood specimens of this case were 399, 216 and 261μg/mL, respectively; although the direct cause of his death was judged as asphyxia due to occlusion of airway with stomach contents, the vomiting was thought to be provoked by buformin poisoning. In this study, marked differences of buformin concentrations between brain tissue and cerebral spiral fluids, and other specimens were observed, which suggested that its distribution was influenced also by blood-brain-barrier. Although a number of buformin poisoning cases were published so far, they gave sporadic data on its concentrations and/or distribution in some limited human specimens. This study is the first to describe detailed distribution/redistribution of buformin in a whole human body quantified by using LC-MS/MS.