Analytical toxicology

Metabolomic Strategies in Biomarker Research-New Approach for Indirect Identification of Drug Consumption and Sample Manipulation in Clinical and Forensic Toxicology?

Drug of abuse (DOA) consumption is a growing problem worldwide, particularly with increasing numbers of new psychoactive substances (NPS) entering the drug market. Generally, little information on their adverse effects and toxicity are available. The direct detection and identification of NPS is an analytical challenge due to their ephemerality on the drug scene. An approach that does not directly focus on the structural detection of an analyte or its metabolites, would be beneficial for this complex analytical scenario and the development of alternative screening methods could help to provide fast response on suspected NPS consumption. A metabolomics approach might represent such an alternative strategy for the identification of biomarkers for different questions in DOA testing. Metabolomics is the monitoring of changes in small (endogenous) molecules (<1,000 Da) in response to a certain stimulus, e.g., DOA consumption. For this review, a literature search targeting "metabolomics" and different DOAs or NPS was conducted. Thereby, different applications of metabolomic strategies in biomarker research for DOA identification were identified: (a) as an additional tool for metabolism studies bearing the major advantage that particularly a priori unknown or unexpected metabolites can be identified; and (b) for identification of endogenous biomarker or metabolite patterns, e.g., for synthetic cannabinoids or also to indirectly detect urine manipulation attempts by chemical adulteration or replacement with artificial urine samples. The majority of the currently available literature in that field, however, deals with metabolomic studies for DOAs to better assess their acute or chronic effects or to find biomarkers for drug addiction and tolerance. Certain changes in endogenous compounds are detected for all studied DOAs, but often similar compounds/pathways are influenced. When evaluating these studies with regard to possible biomarkers for drug consumption, the observed changes appear, albeit statistically significant, too small to reliably work as biomarker for drug consumption. Further, different drugs were shown to affect the same pathways. In conclusion, metabolomic approaches possess potential for detection of biomarkers indicating drug consumption. More studies, including more sensitive targeted analyses, multi-variant statistical models or deep-learning approaches are needed to fully explore the potential of omics science in DOA testing.

Children intoxications: what is abuse and what is not abuse

The curiosity and the natural tendency to explore the environment put young children at an increased risk of poisoning over older children and adults. Poisonings are a significant area of concern from 1 year of age and progressively contribute more to overall rates of morbidity and mortality until children reach adulthood. Particularly, the abuse of children by poisoning is also highly common with thousands of fatalities. A practical strategy is presented that aims to alert health, forensic, and law enforcement professionals to this problem and to demystify the preconception that it is a rare form of abuse or neglect. Compounds that are foreign to a living organism (xenobiotics) and those present within body (endobiotics), mainly involved in children intoxications and contextual examples related to exposure are also reviewed. Particular concern is given to concepts in the field of children poisoning. The described history and the clinical and toxicological evaluation are discussed, and harmonized protocols regarding correct procedures for sample collection to forensic toxicological analysis are proposed. Since children are particularly vulnerable to the toxic effects of high doses of xenobiotics and endobiotics, special consideration on the preparation of the environment that surrounds children in order minimize all possible risks will be also considered.

Cocaine use during pregnancy assessed by hair analysis in a Canary Islands cohort

BACKGROUND

Drug use during pregnancy is difficult to ascertain, and maternal reports are likely to be inaccurate. The aim of this study was to estimate the prevalence of illicit drug use among pregnant women by using maternal hair analysis.

METHODS

A toxicological analysis of hair was used to detect chronic recreational drug use during pregnancy. In 2007, 347 mother-infant dyads were included from the Hospital La Candelaria, Santa Cruz de Tenerife, Canary Islands (Spain). Data on socioeconomic characteristics and on substance misuse during pregnancy were collected using a structured questionnaire. Drugs of abuse: opiates, cocaine, cannabinoids and amphetamines were detected in maternal hair by immunoassay followed by gas chromatography-mass spectrometry for confirmation and quantitation.

RESULTS

Hair analysis revealed 2.6% positivity for cocaine and its metabolites. Use of cocaine during pregnancy was associated with unusual behaviour with potentially harmful effects on the baby.

CONCLUSIONS

The results of the study demonstrate significant cocaine use by pregnant women in Canary Islands. The data should be used for the purpose of preventive health and policy strategies aimed to detect and possibly to avoid in the future prenatal exposure to drugs of abuse.

Postmortem drug levels: innocent bystander or guilty as charged

Determining the etiology or cause of an event in forensic cases often creates many theories. On piece of additional information which may be helpful in cases involving a drug or medication are concentrations or serum levels. Although many confounders can affect the interpretation of the drug level, it is imperative to also relate the data to the clinical scenario presented. Drug levels can be highly variable, depending on the time drawn, location from where the sample was obtained, and reference/references utilized in its interpretation. Postmortem drugs levels often do not reflect the blood levels before death. A drug level can be elevated exclusively because of postmortem distribution. This may result in a conclusion of a poisoning as the cause of death when in fact the death resulted from nonpharmacologic or nontoxicologic causes. Caution is advised from making any conclusions based solely on the drug level; rather an in-depth review of the clinical scenario, reference literature, and drug characteristics are required.