Cocaine Hydroxy Metabolites in Hair: Indicators for Cocaine Use Versus External Contamination☆

Hair toxicological analysis of infants and their mothers: a 5-year retrospective study focusing on cocaine

Prenatal and infant exposure to drugs of abuse is an emerging social and public health problem affecting children health and which may relate to child abuse and neglect. Exposure to drugs of abuse may occur through different routes, including intrauterine, breastfeeding, accidental intake, passive inhalation, and intentional administration. Currently, cases of suspected exposure can be investigated by hair toxicological analysis, the interpretation of which is, however, often difficult, leading to consequent difficulties in the management of such cases. In order to provide a contribution in terms of interpretation of the analytical results, this study aimed to search for the possible existence of elements, from a toxicological point of view, indicative towards the route of exposure. A retrospective study was performed on cases of suspected exposure to drugs of abuse in children aged 0-1 year, evaluated at a University Hospital between 2018 and 2022. Data of children hair toxicological analysis were analyzed and then compared with those of their mothers, when available; 41.6% children tested positive for cocaine. The study found a significant correlation between cocaine and benzoylecgonine concentrations, and a benzoylecgonine/cocaine ratio that tends to decrease as the age of children increases. From the comparison with mothers, a child/mother cocaine concentration ratio lower than 1 was found in all cases of hair sampled within the first week of life, and a ratio greater than or equal to 1 in all cases in which the sampling was performed later. These results, if confirmed in a larger cohort, could represent a contribution in the interpretation of cases of infant exposure to drugs of abuse and be integrated in the context of their multidisciplinary evaluation.

The influence of cosmetic treatments in the uptake of in vitro cocaine contamination in hair

Hair analysis is a powerful tool to assess drug use, yet the challenge of external contamination complicates its interpretation. Understanding the influence of cosmetic hair treatments is pivotal as their presence may affect this phenomenon. This study investigated the effects of four cosmetic treatments (bleach, henna, gel, and dry shampoo) on the external in vitro contamination of cocaine and its primary metabolite, benzoylecgonine (BE). Hair samples were divided into four groups: A-hair treated with cosmetics then contaminated; B-hair contaminated then subjected to cosmetic treatment; and C-hair solely contaminated (control group). Negative hair samples (n = 24) were immersed in a cocaine and BE aqueous solution of 1 μg/mL for 24 h. All hair samples were analyzed by a LC-MSMS procedure successfully validated according to ANSI/ASB Standard 036 guidelines (limit of quantification at 10 pg/mg). Henna in Group A (n = 13) resulted in the most substantial reduction for cocaine (92%), while bleach in Group B (n = 15) showed an 80% decrease. For BE, Group A henna (n = 13) exhibited a 50% reduction, and Group B bleach (n = 15) demonstrated a 71% decrease, all compared to Group C (n = 24). The study found no significant differences concerning hair color (black (n = 3), brown (n = 10), red (n = 5) and blond (n = 6)) or shape (straight (n = 6), wavy (n = 16), curly (n = 1), and coily (n = 1)). All analysis were performed in triplicate with variations below 20%. These findings emphasize that cosmetic treatments do affect cocaine/BE concentrations in hair when exposed to external contamination, highlighting the importance of considering an individual's cosmetic history prior to interpretation.

Establishing effective interpretation criteria in hair analysis to distinguish between passive and active cocaine exposure: Insights from authentic hair samples collected from professional individuals exposed to cocaine

Interpretation results of hair analysis, particularly for cocaine, can be challenging due to the need to differentiate between active use or passive contamination. Our study aimed to assess the impact of varying degrees of passive cocaine exposure hair analysis results and their interpretation. Hair samples (n = 25) were categorized based on the declared cocaine exposure of volunteers: (a) high, involving handling up to several kilograms of cocaine powder from dismantling illegal distribution sites; (b) medium, where staff dealt with cocaine blocks (up to kilograms); and (c) low, with staff in contact with up to grams of cocaine for laboratory analysis. Hair samples were decontaminated using dichloromethane, water, and methanol. The samples and final wash were analyzed for cocaine, benzoylecgonine, norcocaine, cocaethylene, m-OH-benzoylecgonine, and ecgonine methyl ester using a validated UPLC-MS/MS method. Cocaine hair concentrations ranges were as follows (pg/mg): high (n = 53 segments) < LLOQ(32)-7046; medium (n = 91) < LLOQ-939; and low (n = 54) < LLOQ-292. All hair samples had concentrations below the LLOQ for cocaethylene, ecgonine methyl ester, and m-OH-benzoylecgonine. Applying the SoHT cocaine cut-off in combination with a hair/wash ratio criterion identified 97% of the samples as contaminated. This study advocates for a comprehensive approach in evaluating cocaine hair concentrations. This involves integrating the 500 pg/mg decision limit for cocaine with a criterion comparing wash and hair concentration. Additionally, confirming the presence of specific metabolites is crucial. This multifaceted method effectively distinguishes between environmental contamination and active cocaine usage. The research contributes significantly to refining cocaine exposure assessment in professional contexts.

When Substance Use Is Underreported: Comparing Self-Reports and Hair Toxicology in an Urban Cohort of Young Adults

OBJECTIVE

Large-scale epidemiological research often uses self-reports to determine the prevalence of illicit substance use. Self-reports may suffer from inaccurate reporting but can be verified with objective measures. This study examined the following: the prevalence of illicit and non-medical substance use with self-reports and hair toxicology, the convergence of self-reported and objectively quantified substance use, and the correlates of under- and overreporting.

METHOD

The data came from a large urban cohort study of young adults (n = 1,002, mean age = 20.6 years, 50% female). The participants provided 3 cm of hair (covering the previous 3 months) and reported their illicit and non-medical substance use and their sociodemographic, psychological, and behavioral characteristics. Hair toxicology analyses targeted cannabinoids, ketamine, opiates/opioids, stimulants including 3,4-methylenedioxymethamphetamine, and relevant metabolites.

RESULTS

Self-reports underestimated the prevalence of most substances by 30% to 60% compared to hair tests. The average detection ratio (hair test/self-report) was 1.50. Hair tests were typically more sensitive than self-reports. Underreporting was associated with a low level of that substance in hair. Self-reported delinquency and psychopathology were correlated with an increased likelihood of concordant positive self-reports and hair tests compared to underreporting. Overreporting was associated with infrequent self-reported use.

CONCLUSION

Our study suggests that self-reports underestimate young adults' exposure to illicit substances and non-medical use of prescription drugs. Consequently, estimates of associations between substance use and risk factors or outcomes are likely biased. Combining self-reports with hair tests may be most beneficial in study samples with occasional substance use. Researchers can use specific factors (eg, detection ratios) to adjust prevalence estimates and correlations based on self-reports.

A Longitudinal Investigation of Blood Neurofilament Light Chain Levels in Chronic Cocaine Users

The identification of a blood marker of brain pathology that is sensitive to substance-induced neurotoxicity and dynamically responds to longitudinal changes in substance intake would substantially improve clinical monitoring in the field of substance use and addiction. Here, we explored the hypothesis that plasma levels of neurofilament light chain (NfL), a promising marker of neuroaxonal pathology, are elevated in chronic cocaine users and longitudinally associated with changes in cocaine use. Plasma NfL levels were determined using single molecule array (SIMOA) technology at baseline and at a 4-month follow-up. Substance use was subjectively assessed with an extensive interview and objectively measured via toxicological analysis of urine and 4-month hair samples. In a generalized linear model corrected for sex, age, and body mass index, NfL plasma levels were elevated in cocaine users (n=35) compared to stimulant-naïve healthy controls (n=35). A positive correlation between cocaine hair concentration and NfL levels was also found. Changes in cocaine hair concentration (group analysis of increasers vs. decreasers) over the 4-month interval predicted NfL levels at follow-up, indicating a rise in NfL with increased cocaine use and a reduction with decreased use. No associations between use or change of use of other substances (including the neurotoxic cocaine adulterant levamisole) and NfL levels were found. Our findings demonstrate that NfL is a sensitive marker for assessing cocaine-related neuroaxonal pathology, supporting the utility of blood NfL analysis in addiction research but also suggesting the detailed assessment of substance use in neurological studies and diagnostics.

Performance of Hair Testing for Cocaine Use-Comparison of Five Laboratories Using Blind Reference Specimens

The purpose of this study was to compare results from five commercial hair testing laboratories conducting workplace drug testing with regard to bias, precision, selectivity and decontamination efficiency. Nine blind hair specimens, including cocaine-positive drug user specimens (some contaminated with methamphetamine) and negative specimens contaminated with cocaine, were submitted in up to five replicates to five different laboratories. All laboratories correctly identified cocaine in all specimens from drug users. For an undamaged hair specimen from a cocaine user, within-laboratory Coefficients of Variation (CVs) of 5-22% (median 8%) were reported, showing that it is possible to produce a homogenous proficiency testing sample from drug user hair. Larger CVs were reported for specimens composed of blended hair (up to 29%) and curly/damaged hair (19-67%). Quantitative results appeared to be method-dependent, and the reported cocaine concentrations varied up to 5-fold between the laboratories, making interlaboratory comparisons difficult. All laboratories reported at least one positive result in specimens contaminated with cocaine powder, followed by sweat and shampoo treatments. Benzoylecgonine, norcocaine, cocaethylene and hydroxylated cocaine metabolites were all detected in cocaine powder-contaminated specimens. This indicates that current industry standards for analyzing and reporting positive cocaine results are not completely effective at identifying external contamination. Metabolite ratios between meta- or para-hydroxy-cocaine and cocaine were 6- and 10-fold lower in contaminated specimens compared to those observed in cocaine user specimens, supporting their potential use in distinguishing samples positive due to contamination and drug use.

Significance of Metabolite Ratios in the Interpretation of Segmental Hair Testing Results-Differentiation of Single from Chronic Morphine Use in a Case Series

In morphine intoxication cases, forensic toxicologists are frequently confronted with the question of if the individual was opioid-tolerant or opioid-naïve, which can be investigated by hair analysis. However, interpretation of results can be challenging. Here, we report on hair testing for morphine and its metabolite hydromorphone following morphine intoxication without tolerance and upon chronic use. Two consecutive hair samples were collected after a non-fatal intoxication. Analysis comprised short hair segments and their initial wash water solutions. In the intoxications, morphine and hydromorphone levels were 3.3 to 56 pg/mg and at maximum 9.8 pg/mg, respectively. Both levels and hydromorphone to morphine ratios were significantly lower compared to chronic morphine use. In the non-fatal intoxication, the highest hydromorphone to morphine ratio was obtained in the segment corresponding to the time of intoxication. Morphine ratios of wash to hair were significantly higher in the intoxications compared to chronic use, being indicative of sweat/sebum contamination. We recommend including the analysis of hydromorphone and the initial wash solution in cases of morphine intoxications. Our study demonstrates that hydromorphone to morphine ratios can help in distinguishing single from chronic morphine use and in estimating the period of exposure when a consecutive hair sample can be collected in survived intoxications.

A Comprehensive Multi-Analyte Method for Hair Analysis: Substance-Specific Quantification Ranges and Tool for Task-Oriented Data Evaluation

The aim of the present study was to quantify a large number of analytes including opioids, stimulants, benzodiazepines, z-drugs, antidepressants and neuroleptics within a single sample workup followed by a single analytical measurement. Expected drug concentrations in hair are strongly substance dependent. Therefore, three different calibration ranges were implemented: 0.5 to 600 pg/mg (group 1), 10 to 12,000 pg/mg (group 2) and 50 to 60,000 pg/mg (group 3). In order to avoid saturation effects, different strategies were applied for selected transitions including the use of parent mass ions containing one or two 13C-isotopes and detuning of the declustering potential and/or collision energy. Drugs were extracted from pulverized hair by a two-step extraction protocol and measured by liquid chromatrography--tandem mass spectrometry (LC--MS-MS) using Scheduled MRM™ Algorithm Pro. In total, 275 MRM transitions including 43 deuterated standards were measured. The method has been fully validated according to international guidelines. A MultiQuant™ software based tool for task-oriented data evaluation was established, which allows extracting selected information from the measured data sets. The matrix effects and recoveries were within the allowed ranges for the majority of the analytes. The lower limits of quantification (LLOQs) were for ∼72% of the analytes in the low-pg/mg range (0.5-5 pg/mg) and for ∼24% of the analytes between 10 and 50 pg/mg. These LLOQs considered cut-offs by the Society of Hair Testing (SoHT), if recommended. The herein established multi-analyte approach meets the specific requirements of forensic hair testing and can be used for the rapid and robust measurement of a wide range of psychoactive substances. The analyte-specific wide concentration ranges open up a wide field of applications.

Insights into the Decontamination of Cocaine-Positive Hair Samples

A highly discussed step in hair sample preparation for forensic analytics is the applied decontamination. The here presented investigations aim to gain insight and give recommendations on how to conduct this decontamination for the analysis of cocaine consumption in hair. Key insights were gained from the investigation of cocaine consumer hair, which was artificially contaminated in a humid atmosphere with ¹³C₆ labelled cocaine and from cocaine powder contaminated hair. Several decontamination protocols were investigated, whereby the usage of a decontamination protocol consisting of multiple short repetitive washes allowed to visualize the wash out of (¹³C₆-) cocaine. Multiple methanol washes proved to be an efficient and simple decontamination approach. Our findings showed that decontamination protocols can successfully wash out recent cocaine contaminations. They were observed to be rather quickly washed out, whereas cocaine from consumption or “older” cocaine contaminations were shown to eliminate both at a constant rate (from inner hair compartments). Thus, the usage of decontamination protocols to differentiate between consumption and contamination was shown to be limited. As contamination can happen any time at any level, only the application of elaborated decision trees, based on cocaine metabolite ratios and thresholds, can provide the distinction between consumption and contamination. Thus, the authors highly recommend the usage of such tools on all hair samples analyzed for cocaine consumption.

Hydroxycocaines as Metabolic Indicators of Cocaine Ingestion

Hydroxycocaines in hair were investigated with many hundreds of head and body hair samples. All samples were washed by a published extensive aqueous method prior to confirmation by LC-MS/MS. Concentrations, percent of cocaine, and ratios of para- and meta-hydroxycocaines to ortho-hydroxycocaine are presented. Hydroxycocaines as percent of cocaine did not appear to be affected by cocaine concentrations, but were shown to increase with cocaethylene concentrations. Stability of hydroxycocaines over a year of ambient storage was demonstrated. Ortho-hydroxycocaine was shown to be formed by exposure of cocaine-positive hair to peroxide, while para- and meta-hydroxycocaines were not. Presence of para- or meta-hydroxycocaine at > 0.05% of cocaine is proposed as indicating ingestion of cocaine. This indicator prevents black hair from being more likely interpreted as positive for ingestion than lighter colored hair.

What the lab can and cannot do: clinical interpretation of drug testing results

Urine drug testing is one of the objective tools available to assess adherence. To monitor adherence, quantitative urinary results can assist in differentiating "new" drug use from "previous" (historical) drug use. "Spikes" in urinary concentration can assist in identifying patterns of drug use. Coupled chromatographic-mass spectrometric methods are capable of identifying very small amounts of analyte and can make clinical interpretation rather challenging, specifically for drugs that have a longer half-life. Polypharmacy is common in treatment and rehabilitation programs because of co-morbidities. Medications prescribed for comorbidities can cause drug-drug interaction and phenoconversion of genotypic extensive metabolizers into phenotypic poor metabolizers of the treatment drug. This can have significant impact on both pharmacokinetic (PK) and pharmacodynamic properties of the treatment drug. Therapeutic drug monitoring (TDM) coupled with PKs can assist in interpreting the effects of phenoconversion. TDM-PKs reflects the cumulative effects of pathophysiological changes in the patient as well as drug-drug interactions and should be considered for treatment medications/drugs used to manage pain and treat substance abuse. Since only a few enzyme immunoassays for TDM are available, this is a unique opportunity for clinical laboratory scientists to develop TDM-PK protocols that can have a significant impact on patient care and personalized medicine. Interpretation of drug screening results should be done with caution while considering pharmacological properties and the presence or absence of the parent drug and its metabolites. The objective of this manuscript is to review and address the variables that influence interpretation of different drugs analyzed from a rehabilitation and treatment programs perspective.

Using time-of-flight secondary ion mass spectrometry (ToF-SIMS) and matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) for investigations on single hair samples to solve the contamination versus incorporation issue of hair analysis in the case of cocaine and methadone

Drug testing in hair is a controversial subject of discussion. Claims that decontamination protocols could generate false-positive samples, by washing contamination in hair, have unsettled many toxicologists. At least for zolpidem (known for showing only minor contamination), it could be shown that differentiation of the drug incorporated via the bloodstream from contamination was possible. The current work addresses cocaine and methadone, known for their high concentrations and contamination issues. Longitudinally and cross-sectioned samples of drug-soaked hair, consumer hair and cocaine powder contaminated hair were investigated using time of flight-secondary ion mass spectrometry (ToF-SIMS) and matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). In addition, the resulting wash solutions were investigated using LC-MS/MS. Differentiation of contamination from incorporation was possible for soaked and consumer hair samples. Therefore, contamination could be localized in the superficial compartments of hair and could be removed using strong wash protocols. In the case of powder contaminated hair samples, a small amount of cocaine remained in the inner structures even after the application of the strongest wash protocols. However, taking into consideration the differences in their behavior during decontamination steps compared to both soaked and authentic hair samples, the validity of this contamination protocol (rubbing cocaine powder into hair) must be questioned. Furthermore, when using cut-off values and metabolite ratios (from routine hair analysis), the differentiation of incorporation from contamination was possible also for all our experimental samples in this study. Inclusion of metabolites and application of cut-off values are therefore a must in routine hair analysis.