Antemortem Drug Research Articles

Bladder wash as an alternative urine specimen for postmortem toxicology

Urine is the preferred sample in postmortem forensic toxicology to provide evidence of antemortem drug use. However, there are many scenarios in which the bladder is voided or dehydrated prior to their autopsy. In these cases, it is possible to wash the bladder with saline and collect the bladder wash and any residual urine for drug screening and confirmation. The San Francisco Office of the Chief Medical Examiner (OCME) has made the collection of bladder washes at autopsy an option, typically when urine is not available. While bladder washes are not conventional, this study aims to determine its use as an alternative specimen in postmortem forensic toxicology. Laboratory analysis of drugs by LC-MS/MS methodologies and alcohol by HS-GC-FID, was performed. Data from the analyses of bladder wash samples collected at the OCME were analyzed to assess the efficiency of this alternative sample in comparison to urine by determining the identities of individual analytes and their metabolites. Authentic case results showed that bladder wash drug analyses have good sensitivity and selectivity to serve as an alternative specimen when urine is not available. These results are even more so if both individual analytes and metabolites comparisons are considered during data analysis. The bladder wash drug analysis data was also compared to blood analysis data from the OCME to determine if the two were complementary. While bladder wash and blood drug analyses have compatible selectivities, the sensitivity of bladder wash analyses are lower than their blood counterparts. Crucially, in cases where only a bladder wash is analyzed, the detected drugs may provide critical information to a forensic pathologist about the cause and manner of death that would have otherwise not been obtained. Simultaneous to this study, a two-part survey was sent via the NAME list serve to evaluate pathologists’ views of the use of bladder washes before and after reviewing the results of the bladder wash data. This study appears to indicate that standardizing the collection and analysis of bladder washes in postmortem toxicology will provide forensic pathologists with a comprehensive toxicological profile in cases where urine and/or other biological specimens are not available for collection and subsequent analysis. Overall, pathologists were responsive to adopting the practice of collecting bladder washes for toxicological analysis. Bladder washes can serve as an efficient and accurate alternative specimen when there is no urine available to analyze. They are also a reliable alternative specimen to analyze when other specimens, such as blood and vitreous humor, cannot be collected and toxicologically analyzed.

Pharmacogenomics perspective for forensic toxicology: A mini review

Pharmacogenetic and Pharmacogenomics are the study of the association between an individual's genotype and their response to xenobiotics Pharmacokinetic and pharmacodynamics variations can appear at the level of drug-metabolizing enzymes, drug transporters, drug targets or other biomarker genes. Pharmacogenomics can, therefore, be relevant in forensic toxicology. This review presents relevant aspects together with some examples from daily routines. Use of pharmacogenomics in forensic toxicology may add to the understanding of drug toxicity due to genetically predisposed impaired drug metabolism and may provide findings which may be back-extrapolated for the benefits of optimization of antemortem drug therapy.

Postmortem Drug Redistribution: A Compilation of Postmortem/Antemortem Drug Concentration Ratios.

Postmortem drug redistribution (PMR) is a well-known phenomenon in forensic toxicology with implications for medico-legal death investigations. Paired antemortem (AM) specimen and postmortem (PM) mortuary admission femoral blood drug concentrations from 811 coronial cases were used to construct a retrospective compilation of PM/AM drug concentration ratios for 42 parent drugs and metabolites. The median PM/AM ratios for all antidepressants were > 1 and consistent with PMR In contrast, the median PM/AM ratios of most benzodiazepines were < 1. The antipsychotics were varied (0.63-3.3) and suggest the mixed effects of PMR and drug instability. Amphetamines exhibited no trends (0.90-0.95) and are likely confounded by many factors. The PM/AM ratios of cardiovascular drugs, opioids and other drugs are also reported. This research represents an expansive retrospective compilation of paired AM and PM drug concentrations for many toxicologically relevant drugs. While the median PM/AM ratios demonstrate some drug-dependent trends, there was no obvious relationship between AM specimens and PM femoral blood taken at mortuary admission.

Reference Brain/Blood Concentrations of Citalopram, Duloxetine, Mirtazapine and Sertraline.

Postmortem blood samples may not accurately reflect antemortem drug concentrations, as the levels of some drugs increase due to postmortem redistribution (PMR). The brain has been suggested as an alternative sampling site. The anatomically secluded site of the brain limits redistribution and prolongs the detection window, thereby enabling sampling from deceased individuals where blood is no longer suitable for analysis. We report concentrations in brain tissue and blood from 91 cases for the four antidepressants citalopram, duloxetine, mirtazapine and sertraline. The cases were classified according to their role in the cause of death, as follows: (A) concentrations where the drug was the sole cause of fatal intoxication; (B) concentrations where the drug contributed to a fatal outcome; and (C) concentrations where the drug was not related to the cause of death. The analytical method was successfully validated in brain tissue in terms of linearity, process efficiency, precision and accuracy. Quantification of analytes was performed by ultra-performance liquid chromatography with tandem mass spectrometry. Correlations between blood and brain concentrations were achieved with R2-values between 0.67 and 0.91. The following median brain-blood ratios were obtained: 3.71 for citalopram (range: 1.4-5.9), 11.0 for duloxetine (range: 5.0-21.6), 1.53 for mirtazapine (range: 1.02-4.71) and 7.38 for sertraline (range: 3.2-14.2). The S/R ratio of racemic citalopram was the same in brain (0.80) and blood (0.85), whereas the median citalopram/N-desmethylcitalopram ratio was higher in brain (9.1) than blood (4.1). The results of this study may serve as reference concentrations in brain for forensic cases.

İlaçların Postmortem Yeniden Dağılımı Toksikolojik Örnek Alma Veri Değerlendirme ve Yorumlama

Postmortem redistribüsyon ölümden sonra ilaç konsantrasyonlarında meydana gelen değişimleri ifade eder. Akciğer, karaciğer ve miyokard gibi organlardan kan içerisine yeniden dağılımı içerir. Postmortem ilaç konsantrasyonları ilacın karakteristik özelliğine ve örneklemenin alındığı bölgeye dayalı olarak varyasyonlar göstermektedir. Dağılım hacmi, lipofilite ve pKa gibi ilaç özellikleri önemli faktörlerdir. Bazik, lipofilik ve 3 l/kg’dan daha büyük dağılım hacmine sahip ilaçların postmortem yeniden dağılıma uğraması muhtemeldir.Kan örneklemenin yapıldığı anatomik bölge ilaç konsantrasyonunu etkileyebilmektedir. Otopside toplanan kan, önemli bir biyolojik örnektir. Kardiyak ve periferik kandan oluşmaktadır. Kardiyak kan konsantrasyonu genelde periferik kan konsantrasyonundan daha yüksektir. Periferik kandaki postmortem ilaç konsantrasyonunun antemortem ilaç konsantrasyonuna benzer olduğu kaydedilmiştir. Bu yüzden ilaçların analizi ve yorumlanması için periferik bölgeden kanın toplanması önerilir. Pek çok laboratuvar postmortem vakalarda yeniden dağılımı tanımlarken kardiyak:periferik kan (C/P) konsantrasyon oranını kullanır. Bu oran birden daha büyük olduğunda o ilacın postmortem yeniden dağılım göstereceği düşünülür. Postmortem ilaç konsantrasyonu dokularda daha stabil olduğundan dolayı karaciğer: periferik kan (L/P) oranı da postmortem yeniden dağılım belirteci olarak değerlendirilir. Postmortem yeniden dağılımın anımsanmasıyla postmortem kanda tespit edilen ilaç konsantrasyonuna güven azalmakta ve doku analizinin önemi yeniden gündeme gelmektedir.Postmortem dönemde ölçülen ilaç konsantrasyonlarını yorumlamak karışıktır. Bu sebeple çalışmamızda “Postmortem redistribüsyon nedir ve toksikolojik verilerin doğru ve güvenilir değerlendirilmesi için hangi biyolojik örnekler alınmalıdır” sorularına yanıtlar literatür ışığında sunulacaktır.Anahtar Kelimeler: İlaç, Postmortem Yeniden Dağılım, Adli Toksikoloji

Striking increases in postmortem compared to antemortem drug concentrations in a suicidal overdose: A case report

Toxicology testing revealed dramatic increases in whole-blood concentrations of verapamil and diphenhydramine in the short time between hospital admission and death (53 min) in a subject (with a history of overdosing) found unresponsive. While some degree of post-mortem redistribution (PMR) would be expected for the drugs found in this case, PMR cannot explain the considerable increases observed. It is recommended that in potential overdose cases without a clear manner of death but for which ante-mortem and post-mortem specimens (including gastric content) are available, all should be analysed and considered in order to make a more definitive conclusion regarding that death.

Identification of a postmortem redistribution factor (F) for forensic toxicology

Postmortem redistribution (PMR) refers to the changes that may occur in drug concentrations after death. Consequently, postmortem concentrations in blood may not always replicate the antemortem drug levels. Literature supports the model describing drugs with a liver (L) concentration to peripheral blood (P) concentration ratio less than 5 (L/kg) being prone to little or no PMR. Conversely, drugs with a L/P ratio greater than 20 to 30 (L/kg) have propensity for substantial PMR. Expanding upon this prior work, the current paper presents the concept of a postmortem redistribution factor (F) for a drug, which characterizes the direct relationship between postmortem peripheral blood and the corresponding antemortem whole blood concentration. Development of the concept of a "postmortem redistribution factor" will provide a more definitive and authoritative drug ranking, and possibly, numerical interpretation of PMR for forensic toxicologists.

Determination of cocaine and its major metabolite benzoylecgonine in several matrices obtained from deceased individuals with presumed drug consumption prior to death

In the field of forensic toxicology, femoral blood is the most useful sample for the determination and quantification of drugs; however, cases in which blood is unavailable are common. In such cases, validated methodologies for drug determination in alternative matrices can be decisive in the investigation of a case. In particular, when femoral blood is unavailable for analysis for the presence of systemic exposure to cocaine and its principal metabolite, benzoylecgonine, validated methodologies from matrices other than blood that can be obtained in the autopsy room would be useful to the forensic toxicologist in the evaluation of a specific forensic case. To address this issue, we implemented and compared in our study the systematic evaluation of extraction, chromatographic separation, and quantification of cocaine and benzoylecgonine in different biological matrices (right and left cardiac blood, femoral arterial and venous blood, urine, vitreous humor, cerebrospinal fluid, brain accumbens nucleus, brain ventral tegmental area, and liver). The studied matrices were those most likely to be obtained from different autopsy rooms at the time of forensic testing in deceased individuals who are presumed of antemortem drug consumption. Solid phase extraction of analytes from the different matrices was performed using C-8/SCX mixed-phase columns, and gas chromatographic mass spectrometry separation was performed using detection in single-ion monitoring mode. The methodological validation was performed for all the studied matrices, and the results showed similar sensitivity and recoveries without statistical differences between the studied matrices. The methods were applied to evaluate a thanatological case using all the study matrices, showing unequal postmortem distribution of cocaine and benzoylecgonine throughout the different matrices tested. The present work opens the option of applying appropriate methodologies in the analysis of matrices, other than the usual blood, to obtain reliable results that may help clarify a forensic case. In addition, we present findings from different studies. This work affirms not only the potentiality of obtaining reliable data but also reaffirms the challenge of applying these data and taking into account the complexity of interpreting results in matrices other than blood.

Postmortem Drug Redistribution

Postmortem drug concentrations in blood may not always reflect antemortem drug concentrations in blood due to the movement of the drugs after death. The phenomenon is referred to as Postmortem Redistribution (PMR). Mechanisms involved in postmortem redistribution are both complicated and poorly understood. However, postmortem drug concentrations in blood do follow some generally accepted trends that aid with interpretation; the characteristics of the drug itself can be used to indicate if a drug is subject to PMR. Large changes in blood drug concentrations are predicted for basic, lipophilic drugs with a high volume of distribution (>3L/kg). When PMR occurs, blood specimens drawn from the central body cavity and heart generally will have higher drug concentrations postmortem than specimens drawn from peripheral areas, most commonly the femoral vein. The diffusion of drugs from organ tissue into the blood may explain the observed phenomenon [1]. To compensate for PMR, postmortem blood specimens are recommended to be collected from at least two areas of the body at autopsy; a peripheral area and a central area (often the heart), so that a comparison can be made. While antemortem blood specimens are especially helpful in interpreting postmortem blood drug concentrations, relevant specimens are only very rarely available. In a set of case studies of six drugs, drug concentrations in postmortem femoral blood specimens always exceeded the antemortem concentrations in five cases, suggesting that even peripheral blood may still exhibit some redistribution [2]. The study did not, however, report the postmortem interval been death and autopsy. It appeared that a partial answer to the difficulties associated with interpretation of postmortem drug concentrations was provided by two papers published in the 1990s. The first provided detailed information about blood drug concentrations attained from different sites for over fifty drugs [3]. The second provided a tabular list of the drug concentrations from both cardiac and peripheral blood samples expressed as a ratio of cardiac to peripheral blood (C/P) for over one hundred drugs [4]. The C/P ratio became the accepted benchmark with the accepted guideline that “high ratios” were associated with “potential for redistribution” [4]. This guideline was repeated in a review published a few years later that republished the C/P ratios for many of the drugs included in the Dalpe-Scott and coworker’s paper

Effect of antipsychotic drugs on DISC1 and dysbindin expression in mouse frontal cortex and hippocampus

Altered expression of Disrupted-In-Schizophrenia-1 (DISC1) and dysbindin (DTNBP1), susceptibility genes for schizophrenia, in schizophrenic brain has been reported; however, the possible effect of antipsychotics on the expression levels of these genes has not yet been studied. We measured the mRNA expression levels of these genes in frontal cortex and hippocampus of mice chronically treated with typical and atypical antipsychotics by a real-time quantitative RT-PCR method. We found that atypical antipsychotics, olanzapine and risperidone, in a clinically relevant dose increased DISC1 expression levels in frontal cortex, while a typical antipsychotic, haloperidol, did not. No significant effect on dysbindin expression levels was observed in either brain region. These data suggest that prior evidence of decreased expression of dysbindin in postmortem brain of schizophrenics is not likely to be a simple artifact of antemortem drug treatment. Our results also suggest a potential role of DISC1 in the therapeutic mechanisms of certain atypical antipsychotics.

Postmortem studies of the effect of anti-inflammatory drugs on Alzheimer-type pathology and associated inflammation.

Examining postmortem tissue is the most direct way of evaluating the effect of antemortem drug use on the pathological processes believed to be important in Alzheimer's disease (AD). A small number of studies have recently been published in which data from human autopsy tissue and animal models provides important insight into the mechanisms by which anti-inflammatory (AI) agents may protect against AD. These indicate that certain classes of AI drugs may be capable of reducing the chronic inflammation which is consistently seen in AD brain tissue. In addition, a recent study using a transgenic mouse model of AD, suggests that AI therapy may also influence the accumulation of senile plaques and dystrophic neurites. The results of these and future postmortem studies will be invaluable in the development of optimum treatment strategies.

The Use of Vitreous Humor as an Alternative to Whole Blood for the Analysis of Benzodiazepines

In postmortem drug analysis, the most commonly used sample matrix is whole blood. However, postmortem changes can denature this matrix, resulting in a loss or degradation of drugs, thus biasing analytical findings. Vitreous humor is thought to be less affected by these changes and should, therefore, have the potential to provide a more reliable estimation of antemortem drug concentrations. To assess the usefulness of vitreous humor for the analysis of benzodiazepine drugs, vitreous humor and whole blood were obtained postmortem in 27 cases. Three benzodiazepine drugs were investigated-temazepam, diazepam, and desmethyldiazepam. For temazepam and diazepam, some correlation was found between the matrices (R2 = 0.789 and 0.724, respectively). However, for desmethyldiazepam, no correlation was observed (R2 = 0.068). Regression analysis on plots of vitreous humor versus blood concentrations produced gradients of less than 1.0 showing that, in general, levels in blood are higher than the corresponding levels in vitreous humor.

Estimating antemortem drug concentrations from postmortem blood samples: the influence of postmortem redistribution

Aims—To compare blood drug concentrations during life with postmortem drug concentrations measured from a peripheral site and a central site. Methods—Coroner's cases from October 1990 to July 1997 were reviewed....

Application of the novel immunoassay TRIAGE to a rapid detection of antemortem drug abuse.

The applicability of the immunoassay TRIAGE (E. Merck, Darmstadt, Germany) as a simple and rapid assay for antemortem drug abuse was tested on 100 urine samples from forensic autopsies. The samples were also analyzed by fluorescence polarization immunoassay and by chromatographic methods. The confirmation rate of the TRIAGE results by chromatographic analysis was 92% for benzodiazepines, 95% for cannabinoids, 96% for cocaine, 100% for opiates and barbiturates, and 82% for amphetamines. Because the urine samples were taken from corpses, the latter finding can be explained by false-positive amphetamine results due to cross-reactivity of the antibodies used in current immunoassay technologies with phenylalkylamines, which are generated in postmortem decomposition processes. In fact, tyramine, a typical product of putrefaction, was identified by gas chromatography-mass spectrometry in 11 samples of false-positive amphetamine determinations. TRIAGE produces positive amphetamine results for samples containing tyramine in concentrations of more than 5 mg/L. The detection limit of the TRIAGE assay for 7-aminoflunitrazepam, the major urinary metabolite of flunitrazepam, is within the range of 0.5-1 mg/L.

URBAN FIREARM DEATHS

Firearm violence is an ever-increasing element in the lives of the U.S. urban population. This study examined the trends in firearm violence and victims during a 5-year period in the city of Philadelphia. Medical Examiner records of all deaths in Philadelphia County in 1985 and 1990 were reviewed. Demographic, autopsy, and criminal record information was analyzed. There were 145 firearm homicide victims in 1985 versus 324 in 1990, a 123% increase. This was primarily because of deaths among young (age 15-24 years), black male victims. Handguns were involved in at least 90% of firearm homicides in both study years. The use of semiautomatic handguns increased from 24% to 39% during the study period. In 1985, 42% of revolver homicides died at the scene, versus 18% in 1990. However, 5% of victims of semiautomatic weapons fire died at the scene in 1985 versus 34% in 1990. The decrease in survival of semiautomatic weapon victims occurred despite the implementation of six trauma centers within the county, and probably reflects a shift toward high-velocity, high-caliber ammunition. Antemortem drug use and criminal history was common. A total of 54% of victims were intoxicated in 1985 and 61% were in 1990. Cocaine became the most common intoxicant in 1990, with 39% of victims using it during the antemortem period. The percentage of victims with a criminal record increased from 44% to 67%. Although the duration of criminal history decreased from 14 to 6 years, the number of patients with previous drug offenses increased from 33% to 84%..(ABSTRACT TRUNCATED AT 250 WORDS)

Postmortem disposition of morphine in rats

The antemortem and postmortem distribution of morphine was studied in rats for the purpose of establishing whether drug distribution is altered after death. Samples were examined for free and total morphine concentration, pH and water content at 0–96 h after death. Morphine was administered antemortem at various intervals. All groups of rats studied showed a significant ( P < 0.05) increase in postmortem cardiac blood morphine concentrations. These changes, which are detectable within 5 min after death are likely to be related to an observed, rapid decrease in cardiac blood pH from 7.34 ± 0.02 to 6.74 ± 0.05. Significant increases in free morphine levels were, also, observed 24 and 96 h after death in liver, heart and forebrain while urine morphine levels decreased. The liver showed the greatest increase (20-fold) in free morphine levels 96 h after death, while hindbrain levels did not significantly change. Bacterial hydrolysis of morphine glucuronides accounted only in part for the observed increase in free morphine concentration. Postmortem fluid movement and pH-dependent drug partitioning was detected. It would appear that several mechanisms are responsible for postmortem drug distribution. Understanding the mechanisms and patterns responsible may eventually lead to better choices of postmortem tissue which may better represent antemortem drug levels.

A Review of Disposition of Toxic Drugs and Chemicals in Man, Volume 1

Abstract This first volume of a two-volume series presents pertinent toxicological information on more than 100 drugs ranging from ethanol to nitrous oxide. The drugs are presented alphabetically within general sections. A brief review format with citations current through 1977 includes pertinent data on drug history, metabolic parameters, structure, tissue distribution, and analytical methods. In particular, plasma concentrations, drug halflife, and urinary excretion rate following low or therapeutic doses are well delineated for most drugs. This type of reference information will be especially useful for clinical toxicologists who provide interpretive assistance to clinicians. In addition, each review includes current information on postmortem blood and tissue concentrations following overdose that will assist forensic toxicologists in their evaluations of antemortem drug abuse. Although details of methods are not included in the review, the author does provide a variety of current references to published methods for each drug.