The importance of sample size with regard to the robustness of postmortem reference values

Fatal concentrations of antidepressant and antipsychotic drugs in postmortem femoral blood

Antidepressants and antipsychotics are both an important class of prescription drugs within postmortem (PM) toxicology because most of the substances are toxic in overdose and the mental disorders being treated may be associated with suicidality. A wide range of antidepressants and antipsychotics are currently included in up-to-date PM toxicology analysis protocols. However, apart from case studies, few reports on fatal concentrations based on large number of cases have been published in the literature. Based on PM investigations in Finland between 2000 and 2020, this study provides fatal reference concentrations in poisonings due to an antidepressant or an antipsychotic drug assigned as the principal intoxicant. Summary statistics for drug concentrations in PM femoral blood (min, max, mean, 10th, 25th, 50th, 75th, 90th percentile) were calculated for 17 antidepressant (N = 2,007) and for 12 antipsychotic drugs (N = 1,161). The proportion of suicide, accident and undetermined manner of death is indicated for each drug. Further, the fatal concentrations obtained in this study were evaluated by comparison with fatal and "normal" PM concentrations reported by two previously published approaches, the grouped causes of death approach and the all causes of death approach, respectively. This study shows that, despite the well-known variation in PM drug concentrations, competently generated fatal concentration results for the drugs studied are consistent to such an extent that they can be used as a reference in the interpretation process.

A model of evaluative opinion to encourage greater transparency and justification of interpretation in postmortem forensic toxicology

Over the past decades, the calls to improve the robustness of interpretation in forensic science have increased in magnitude. Forensic toxicology has seen limited progress in this regard. In this work, we propose a transparent interpretive pathway for use in postmortem forensic toxicology cases. This process allows the selection of the interpretive methodology based on the amount of previous information that is available for the drug(s) in question. One approach is an assessment of various pharmacological and circumstantial considerations resulting in a toxicological significance score (TSS), which is particularly useful in situations where limited information about a drug is available. When there is a robust amount of case data available, then a probabilistic approach, through the evaluation of likelihood ratios by the forensic toxicologist and of prior probabilities by the fact finder, is utilized. This methodology provides a transparent means of making an interpretive decision on the role of a drug in the cause of death. This will allow the field of forensic toxicology to take a step forward in using best practice in evaluative reporting, a tool already used by many other forensic science disciplines.

Common opioids and stimulants in autopsy and DUID cases: A comparison of measured concentrations

Quantitative results from toxicological analyses of autopsy material are widely compared to ranges in reference works to determine if drug concentrations are in relevant levels for establishing intoxication. This study compares concentrations of commonly used opioids and stimulants from drug addict autopsies and driving under the influence of drugs (DUID) cases to supplement current knowledge of the possible span and overlaps of measured concentrations. The study included whole-blood results from forensic autopsies of drug addicts performed from 2015 to 2020 (n = 220) and DUID cases from 2015 to 2019 (n = 7088). The focus was on heroin/morphine, methadone, cocaine, amphetamine and MDMA concentrations because these drugs are commonly encountered in both fatal intoxications and DUID cases and the potential for abuse is well known. In the DUID group, the opioids heroin/morphine and methadone and the stimulants amphetamine and MDMA were often seen in concentrations above the reported lower comatose-fatal level whereas cocaine was almost always below. Thus, based on our data, the potential for false assessment of intoxication cases when comparing to reported comatose-fatal limits appears greatest on lower end concentrations of heroin/morphine, methadone, amphetamine and MDMA, whereas false assessment of cocaine appears less likely because most control cases are below reported comatose-fatal levels.

Oxycodone-Related Deaths: The Significance of Pharmacokinetic and Pharmacodynamic Drug Interactions

BACKGROUND AND OBJECTIVES

Oxycodone is frequently prescribed as well as detected in postmortem cases. Concurrent use of pharmacodynamically or pharmacokinetically interacting drugs can cause adverse effects or even fatal intoxication. The aims of this study were to investigate differences in prescriptions for and toxicological findings of pharmacodynamically and pharmacokinetically interacting drugs in fatal oxycodone-related intoxications and other causes of death. We also aimed to investigate the differences in prevalence of oxycodone prescriptions, and the detected postmortem oxycodone concentrations between fatal oxycodone-related intoxications and other causes of death.

METHODS

Forensic autopsy cases (2012-2018) where oxycodone was identified in femoral blood (n = 1236) were included. Medical history and prescription data were retrieved from national databases and linked to the forensic toxicology findings.

RESULTS

Oxycodone-related deaths were found to have higher blood concentrations of oxycodone (median 0.30 µg/g vs. 0.05 µg/g) and were less likely to have a prescription for oxycodone (OR 0.62) compared to nonintoxication deaths. Pharmacodynamically interacting drugs were prescribed in 79% and found in blood in 81% of the cases. Pharmacokinetically interacting drugs were rarely prescribed (1%). Oxycodone-related deaths were more likely to have prescriptions for a pharmacodynamically interacting drug (OR 1.7) and more often have co-findings of one or multiple pharmacodynamically interacting drugs (OR 5.6).

CONCLUSION

The results suggest that combined use of oxycodone and pharmacodynamically interacting drugs is associated with oxycodone-related death and that non-medical use of oxycodone is a potential risk factor for oxycodone-related intoxication.

Summary statistics for drugs and alcohol concentration recovered in post-mortem femoral blood in Western Switzerland

In post-mortem investigations of fatal intoxication, it is challenging to determine which drug(s) were responsible for the death, and which drugs did not. This study aims to provide post-mortem femoral blood drug levels in lethal intoxication and in post-mortem control cases, where the cause of death was other than intoxication. The reference values could assist in the interpretation of toxicological results in the routine casework. To this end, all post-mortem toxicological results in femoral blood from 2011 to 2017 in Western Switzerland were considered. A full autopsy with systematic toxicological analysis (STA) was conducted in all cases. Results take into account the cause of death classified into one of four categories (as published by Druid and colleagues): I) certified intoxication by one substance alone, IIa) certified intoxication by more than one substance, IIb) certified other causes of death with incapacitation due to drugs, and III) certified other causes of death without incapacitation due to drugs. This study includes 1 990 post-mortem cases where femoral blood was analysed. The material comprised 619 women (31%) and 1 371 men (69%) with a median age of 50 years. The concentrations of the 32 most frequently recorded substances as well as alcohol are discussed. These include 6 opioids and opiates, 3 antidepressants, 6 neuroleptics and hypnotics, 1 barbiturate, 11 benzodiazepines (and related drugs), 2 amphetamine-type stimulants, cocaine, paracetamol, and tetrahydrocannabinol (THC). The most common substances that caused intoxication alone were morphine, methadone, ethanol, tramadol, and cocaine. The post-mortem concentration ranges for all substance are categorized as I, IIa, IIb, or III. Statistical post-mortem reference concentrations for drugs are discussed and compared with previously published concentrations. This study shows that recording and classifying cases is time-consuming, but it is rewarding in a long-term perspective to achieve a more reliable information about fatal and non-fatal blood concentrations.