Rapid and robust on-scene detection of cocaine in street samples using a handheld near-infrared spectrometer and machine learning algorithms.

On-scene drug detection is an increasingly significant challenge due to the fast-changing drug market as well as the risk of exposure to potent drug substances. Conventional colorimetric cocaine tests involve handling of the unknown material and are prone to false-positive reactions on common pharmaceuticals used as cutting agents. This study demonstrates the novel application of 740-1070 nm small-wavelength-range near-infrared (NIR) spectroscopy to confidently detect cocaine in case samples. Multistage machine learning algorithms are used to exploit the limited spectral features and predict not only the presence of cocaine but also the concentration and sample composition. A model based on more than 10,000 spectra from case samples yielded 97% true-positive and 98% true-negative results. The practical applicability is shown in more than 100 case samples not included in the model design. One of the most exciting aspects of this on-scene approach is that the model can almost instantly adapt to changes in the illicit-drug market by updating metadata with results from subsequent confirmatory laboratory analyses. These results demonstrate that advanced machine learning strategies applied on limited-range NIR spectra from economic handheld sensors can be a valuable procedure for rapid on-site detection of illicit substances by investigating officers. In addition to forensics, this interesting approach could be beneficial for screening and classification applications in the pharmaceutical, food-safety, and environmental domains.

Aptamer-based cocaine assay using a nanohybrid composed of ZnS/Ag2Se quantum dots, graphene oxide and gold nanoparticles as a fluorescent probe.

Authors report on a new fluoro-graphene-plasmonic nanohybrid aptamer-based fluorescent nanoprobe for cocaine. To construct the nanoprobe, newly synthesized glutathione-capped ZnS/Ag2Se quantum dots (QDs) were first conjugated to graphene oxide (GO) to form a QD-GO nanocomposite. The binding interaction resulted in a fluorescence turn-ON. Thereafter, cetyltrimethylammonium bromide (CTAB)-gold nanoparticles (AuNPs) were directly adsorbed on the QD-GO nanocomposite to form a novel QD-GO-CTAB-AuNP nanohybrid assembly that resulted in a fluorescence turn-OFF. Streptavidin (strep) was then adsorbed on the QDs-GO-CTAB-AuNP nanohybrid assembly which allowed binding to a biotinylated MNS 4.1 anticocaine DNA aptamer (B) receptor. The addition of cocaine into the strep-B-QDs-GO-CTAB-AuNP aptamer nanoprobe system aided affinity to the aptamer receptor and in turn turned on the fluorescence of the nanoprobe in a concentration-dependent manner. Under optimum experimental conditions, we found the strep-B-QD-GO-CTAB-AuNP to be far superior in its sensitivity to cocaine than the tested strep-B-QDs (no GO and CTAB-AuNPs), strep-B-QD-CTAB-AuNP (no GO) and strep-B-QD-GO (no CTAB-AuNP). In addition, the investigation of localized surface plasmon resonance (LSPR) amplified signal from tested plasmonic NPs shows that CTAB-AuNPs was far superior in amplifying the fluorescence signal of the nanoprobe. A detection limit of 4.6 nM (1.56 ng.mL-1), rapid response time (~2 min) and excellent selectivity against other drugs, substances and cocaine metabolites was achieved. The strep-B-QD-GO-CTAB-AuNP aptamer-based fluorescent nanoprobe was successfully applied for the determination of cocaine in seized adulterated cocaine samples. Graphical abstractSchematic representation of the streptavidin-biotin-quantum dot-graphene oxide-cetyltrimethylammonium bromide-gold nanoparticle aptamer-based fluorescent nanoprobe for cocaine.

Determination of hydroxy metabolites of cocaine in hair samples for proof of consumption.

Although hair is widely used to identify drug use, there is a risk of false positives due to environmental contamination. This especially applies to cocaine (COC). Several strategies such as detection of norcocaine (NCOC) or cocaethylene, metabolite concentration ratios or intricate washing procedures have been proposed to differentiate actual use from contamination. The aim of the present study was to identify hydroxy metabolites of COC in hair specimens, thus enabling unambiguous prove of ingestion. A suspect screening of 41 COC-positive samples for these compounds was performed by liquid chromatography-quadrupole time of flight-mass spectrometry (LC-QTOF-MS). Once identified, mass transitions for o-, p- and m-isomers of hydroxy COC as well as p- and m-isomers of hydroxy benzoylecgonine (BE) and hydroxy NCOC were introduced into a routine procedure for testing drugs of abuse in hair by liquid chromatography-tandem mass spectrometry (LC-MS/MS) which was applied to 576 hair samples. Hydroxy metabolites were present in 92.2% of COC-positive hair samples; their detection rate exceeded that of cocaethylene and NCOC. Moreover, p-OH-BE, m-OH-BE as well as p-OH-NCOC and m-OH-NCOC have been identified for the first time in COC-positive hair specimens. Hydroxy cocainics could be detected in samples having a negative conclusion on drug use applying hitherto established criteria. We suggest a more conclusive interpretation outcome including detection of hydroxy metabolites into the evaluation of COC-positive hair samples.

A universal aptameric biosensor: Multiplexed detection of small analytes via aggregated perylene-based broad-spectrum quencher.

A universal aptameric system based on the taking advantage of double-stranded DNA/perylene diimide (dsDNA/PDI) as the signal probe was developed for multiplexed detection of small molecules. Aptamers are single-stranded DNA or RNA oligonucleotides which are selected in vitro by a process known as systematic evolution of ligands by exponential enrichment. In this work, we synthesized a new kind of PDI and reported this aggregated PDI could quench the double-stranded DNA (dsDNA)-labeled fluorophores with a high quenching efficiency. The quenching efficiencies on the fluorescence of FAM, TAMRA and Cy5 could reach to 98.3%±0.9%, 97.2%±0.6% and 98.1%±1.1%, respectively. This broad-spectrum quencher was then adopted to construct a multicolor biosensor via a label-free approach. A structure-switching-triggered enzymatic recycling amplification was employed for signal amplification. High quenching efficiency combined with autocatalytic target recycling amplification afforded the biosensor with high sensitivity towards small analytes. For other targets, changing the corresponding aptamer can achieve the goal. The quencher did not interfere with the catalytic activity of nuclease. The biosensor could be manipulated with similar sensitivity no matter in pre-addition or post-addition manner. Moreover, simultaneous and multiplexed analysis of several small molecules in homogeneous solution was achieved, demonstrating its potential application in the rapid screening of multiple biotargets.

Screening for illicit drugs in pooled human urine and urinated soil samples and studies on the stability of urinary excretion products of cocaine, MDMA, and MDEA in wastewater by hyphenated mass spectrometry techniques.

Monitoring population drug use through wastewater-based epidemiology (WBE) is a useful method to quantitatively follow trends and estimate total drug consumption in communities. Concentrations of drug biomarkers might be low in wastewater due to dilution; and therefore analysis of pooled urine (PU) is useful to detect consumed drugs and identify targets of illicit drugs use. The aims of the study were (1) to screen PU and urinated soil (US) samples collected at festivals for illicit drug excretion products using hyphenated techniques; (2) to develop and validate a hydrophilic interaction liquid chromatography - mass spectrometry / mass spectrometry (HILIC-MS/MS) method of quantifying urinary targets of identified drugs in wastewater; and (3) to conduct a 24 h stability study, using PU and US to better reflect the chemical environment for targets in wastewater. Cocaine (COC) and ecstasy-like compounds were the most frequently detected illicit drugs; an analytical method was developed to quantify their excretion products. Hydroxymethoxymethamphetamine (HMMA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), HMMA sulfate (HMMA-S), benzoylecgonine (BE), and cocaethylene (CE) had 85-102% of initial concentration after 8 h of incubation, whereas COC and ecgonine methyl ester (EME) had 74 and 67% after 8 h, respectively. HMMA showed a net increase during 24 h of incubation (107% ± 27, n = 8), possibly due to the cleavage of HMMA conjugates, and biotransformation of MDMA. The results suggest HMMA as analytical target for MDMA consumption in WBE, due to its stability in wastewater and its excretion as the main phase I metabolite of MDMA. Copyright © 2016 John Wiley & Sons, Ltd.

Applicability of ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry for cocaine profiling.

For the first time in China, the chemical profiling of cocaine specimens was performed at the National Narcotics Laboratory. An ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UHPLC-QTOF-MS) method was developed and validated for simultaneous analysis of 14 cocaine alkaloids and 5 main adulterants. Among them, ecgonine methyl ester, ecgonine, benzoylecgonine, and norcocaine were identified by comparing with the standard materials; tropacocaine, 3,4,5-trimethoxycocaine, cis-/trans-cinnamoylcocaine were tentatively identified based on the exact masses of protonated molecules and product ions; six unidentified alkaloids of 182/1.47, 316/9.54, 659/9.85, 316/9.87, 420/10.34, and 420/10.85 were marked with 'extracted mass/retention time' for convenience. Minimum sample preparation and analysis time were required, which was suitable for routine analysis. Based on the semi-quantitative data set of 14 alkaloid impurities in 131 linked/unlinked cocaine samples, 50 combinations of pretreatment methods and distance/correlation measurements were tested for their potential discrimination power for cocaine profiling, and Logarithm/Pearson exhibited the best result. After hierarchical cluster analysis (HCA), 183 cocaine samples collected from 2011 to 2015 were classified into 7 major groups. Moreover, 37 groups of linked samples were found within and between provinces, which provide intelligence for the case connection and revealing of the distribution networks. Our results highlighted the practical utilities of drug profiling, especially to support the investigation through operational intelligence and to improve the knowledge related to the drug trafficking through strategic intelligence. Copyright © 2016 John Wiley & Sons, Ltd.

Norcocaine and cocaethylene distribution patterns in hair samples from light, moderate, and heavy cocaine users.

Even though hair analysis often seems to be the best choice for retrospective monitoring of cocaine intake, differentiating between incorporated cocaine and external contamination is widely debated. In this study we report results obtained in 90 hair samples from addicts. All samples were analyzed for cocaine, benzoylecgonine, norcocaine, cocaethylene, and tropococaine by gas chromatography-mass spectrometry (GC-MS) techniques coupled with direct immersion solid-phase micro-extraction. Cocaine concentrations were stratified into three classes of usage: light (0.5-3 ng/mg), moderate (3.1-10 ng/mg) and heavy (10.1-40 ng/mg). The Substance Abuse and Mental Health Services Administration cut-off criteria for establishing active cocaine use were applied to the results. For all samples criteria were cocaine levels above 0.5 ng/mg (ranging from 1.63 to 39.29 ng/mg, mean 9.49 ng/mg), benzoylecgonine concentrations ≥ 0.05 ng/mg (ranging from 0.19 to 5.77 ng/mg, mean 1.40), and benzoylecgonine to cocaine % ratio ≥5% (from 6.43 to 26.09%). Norcocaine was present in 58.9% of samples (concentration range: 0.22-3.14 ng/mg) and was strongly predictive only of heavy cocaine use (sensitivity 100% for cocaine concentrations above 9.58 ng/mg). Twenty hair samples from moderate and heavy users tested positive for cocaethylene (concentration range: 0.22-1.98 ng/mg, mean 0.73 ng/mg). This study on hair samples with no chance of false positive cases highlights the very limited applications of testing minor cocaine metabolites for definitive proof of active cocaine consumption. © 2015 The Authors. Drug Testing and Analysis Published by John Wiley & Sons, Ltd.

Automated Fast Screening Method for Cocaine Identification in Seized Drug Samples Using a Portable Fourier Transform Infrared (FT-IR) Instrument.

Quick and presumptive identification of seized drug samples without destroying evidence is necessary for law enforcement officials to control the trafficking and abuse of drugs. This work reports an automated screening method to detect the presence of cocaine in seized samples using portable Fourier transform infrared (FT-IR) spectrometers. The method is based on the identification of well-defined characteristic vibrational frequencies related to the functional group of the cocaine molecule and is fully automated through the use of an expert system. Traditionally, analysts look for key functional group bands in the infrared spectra and characterization of the molecules present is dependent on user interpretation. This implies the need for user expertise, especially in samples that likely are mixtures. As such, this approach is biased and also not suitable for non-experts. The method proposed in this work uses the well-established "center of gravity" peak picking mathematical algorithm and combines it with the conditional reporting feature in MicroLab software to provide an automated method that can be successfully employed by users with varied experience levels. The method reports the confidence level of cocaine present only when a certain number of cocaine related peaks are identified by the automated method. Unlike library search and chemometric methods that are dependent on the library database or the training set samples used to build the calibration model, the proposed method is relatively independent of adulterants and diluents present in the seized mixture. This automated method in combination with a portable FT-IR spectrometer provides law enforcement officials, criminal investigators, or forensic experts a quick field-based prescreening capability for the presence of cocaine in seized drug samples.

Ultra-high frequency piezoelectric aptasensor for the label-free detection of cocaine.

This paper describes a label-free and real-time piezoelectric aptasensor for the detection of cocaine. The acoustic wave sensing platform is a quartz substrate functionalized with an adlayer of S-(11-trichlorosilyl-undecanyl)-benzenethiosulfonate (BTS) cross-linker onto which the anti-cocaine MN4 DNA aptamer is next immobilized. Preparation of the sensor surface was monitored using X-ray photoelectron spectroscopy (XPS), while the binding of cocaine to surface-attached MN4 was evaluated using the electromagnetic piezoelectric acoustic sensor (EMPAS). The MN4 aptamer, unlike other cocaine aptamer variants, has its secondary structure preformed in the unbound state with only tertiary structure changes occurring during target binding. It is postulated that the highly sensitive EMPAS detected the binding of cocaine through target mass loading coupled to aptamer tertiary structure folding. The sensor achieved an apparent Kd of 45 ± 12 µM, and a limit of detection of 0.9 µM. Repeated regenerability of the sensor platform was also demonstrated. This work constitutes the first application of EMPAS technology in the field of aptasensors. Furthermore, it is so far one of the very few examples of a bulk acoustic wave aptasensor that is able to directly detect the binding interaction between an aptamer and a small molecule in a facile one-step protocol without the use of a complex assay or signal amplification step.

Preparation of longitudinal sections of hair samples for the analysis of cocaine by MALDI-MS/MS and TOF-SIMS imaging.

Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) for the analysis of intact hair is a powerful tool for the detection of drugs of abuse in toxicology and forensic applications. Here we present a quick, easy, and reproducible method of preparing longitudinal sections of single hairs. This method improves the accessibility of chemicals embedded in the hair matrix for molecular imaging with mass spectrometry. The images obtained from a single, sectioned hair sample show molecular distributions in the exposed medulla, cortex, and a portion of the cuticle observed as a narrow layer surrounding the cortex. Using MALDI-MS/MS imaging, the distribution of cocaine was observed throughout five longitudinally sectioned drug-user hair samples. The images showed the distribution of the product ion at m/z 182, derived from the precursor ion of cocaine at m/z 304. MetA-SIMS images of longitudinally sectioned hair samples showed a more detailed distribution of cocaine at m/z 304, benzoylecgonine the major metabolite of cocaine at m/z 290 and other drugs such as methadone which was observed at m/z 310. Chronological information of drug intake can be obtained more sensitively. The chronological detail is in hours rather than months, which is of great interest in clinical as well as forensic applications.

Indirect competitive assays on DVD for direct multiplex detection of drugs of abuse in oral fluids.

On-site oral fluid testing for drugs of abuse has become prominent in order to take immediate administrative action in an enforcement process. Herein, we report a DVD technology-based indirect competitive immunoassay platform for the quantitative detection of drugs of abuse. A microfluidic approach was adapted to prepare multiplex immunoassays on a standard DVD-R, an unmodified multimode DVD/Blu-Ray drive to read signal, and a free disc-quality analysis software program to process the data. The DVD assay platform was successfully demonstrated for the simultaneous, quantitative detection of drug candidates (morphine and cocaine) in oral fluids with high selectivity. The detection limit achieved was as low as 1.0 ppb for morphine and 5.0 ppb for cocaine, comparable with that of standard mass spectrometry and ELISA methods.

Determination of stimulants using gas chromatography/high-resolution time-of-flight mass spectrometry and a soft ionization source.

RATIONALE: The aim of this study was to investigate the mass spectral fragmentation of a small set of stimulants in a high-resolution time-of-flight mass spectrometer equipped with a soft ionization source using vacuum ultraviolet (VUV) photons emitted from different plasma gases. It was postulated that the use of a plasma gas such as Xe, which emits photons at a lower energy than Kr or Ar, would lead to softer ionization of the test compounds, and thus to less fragmentation. METHODS: A set of nine stimulants: cocaine, codeine, nicotine, methadone, phenmetrazine, pentylenetetrazole, niketamide, fencamfamine, and caffeine, was analyzed by gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) in positive ion mode with this soft ionization source, using either Xe, Kr, or Ar as plasma gases. Working solutions of the test compounds at 0.1 to 100 ng/µL were used to establish instrument sensitivity and linearity. RESULTS: All test compounds, except methadone and pentylenetetrazole, exhibited strong molecular ions and no fragmentation with Xe-microplasma photoionization (MPPI). Methadone exhibited significant fragmentation not only with Xe, but also with Kr and Ar, and pentylenetetrazole could not be ionized with Xe, probably because its ionization energy is above 8.44 eV. The Kr- and Ar-MPPI mass spectra of the test compounds showed that the relative intensity of the molecular ion decreased as the photon energy increased. CONCLUSIONS: When coupled to a TOF mass spectrometer this soft ionization source has demonstrated signal-to-noise (S/N) ratios from 7 to 730 at 100 pg per injection (depending on the compound), and a dynamic range of three orders of magnitude (100 pg to 100 ng) for some of the test compounds.

Spectrofluorimetric determination of nomifensine in human plasma and urine by derivatization with fluorescamine.

A sensitive, simple and rapid spectrofluorimetric method was developed for the determination of nomifensine in human plasma and urine. The present method was based on the derivatization by fluorescamine in phosphate buffer at pH 4.0 to produce a highly fluorescent product which was measured at 488 nm (excitation at 339 nm). The method was validated according to the ICH guidelines with respect to linearity, limit of detection, limit of quantification, accuracy, precision, recovery and robustness. The assay was linear over the concentration ranges 100-2,000 and 50-2,000 ng/mL for plasma and urine, respectively. The limits of detection were calculated to be 13.9 and 7.5 ng/mL for plasma and urine, respectively. The method was successfully applied to the analysis of the drug in human plasma and urine.

Exposure to psychoactive substances in women who request voluntary termination of pregnancy assessed by serum and hair testing.

Drug abuse is a worldwide phenomenon with significant health and socioeconomic impact and it is of particular concern in women of reproductive age and in pregnant women. We aimed to investigate the prevalence of drug use by serum and hair testing in a cohort of pregnant women at 12th week gestation who decided voluntarily to interrupt their pregnancy and to investigate the relationship between drug exposure and induced abortions (IA), repeated IA and contraception. The study was conducted in an obstetrics clinic authorised to perform IA in Murcia, Spain during an 18 months period (2007-2009). Apart from serum and/or hair testing, the 142 women enrolled in the study completed a detailed questionnaire regarding drug, alcohol and tobacco use in the previous 3 months. Serum and hair samples were analyzed by gas chromatography mass spectrometry assays. Hair and serum samples showed a 30% overall positivity to drugs of abuse. Of these samples, 20.4, 14.1, 4.2 and 1.4% were positive for cannabinoids, cocaine, opiates, and MDMA, respectively, with polydrug use in 5.6% cases. In this cohort, a positive association was found between drug use and repeated IA. The results highlight the need for promoting pregnancy planning for young women in general, especially when consuming psychoactive substances as well as promote safe and accessible contraception in women of reproductive age. In women requesting IA, specific drug abuse counselling should be implemented.

Stability of cocaine in formalin solution and fixed tissues.

Embalming and formalin fixation are common, and yet they can create problems for the forensic scientist if a drug has been the cause of death and if the only available specimens to be analyzed are formalin-fixed tissues. Previous studies have demonstrated that during fixation xenobiotics are extracted into formalin according to tissue and fixing solution characteristics. In some cases formalin can react with the analyte resulting in the production of new chemical entities. Regarding cocaine and its metabolites, Cingolani et al. have reported that formalin-fixation extracts benzoylecgonine (BE) from tissues and that BE is stable in the fixing solution. However, the stability and kinetic properties of cocaine remain so far unexplored. Our data show that in buffered formalin (pH 7.4) cocaine is hydrolyzed to BE in agreement with a pseudo first-order reaction kinetic (half-life time approximately 7 days), whereas in unbuffered formalin (pH approximately 3.5) it is relatively stable over a period of 30 days. The analysis of brain and liver samples at different fixation times indicates that during fixation an extraction process occurs for both analytes and that the extraction is more efficient in the liver than in the brain, probably because of a greater lipophilicity of the brain tissue. In conclusion, our study demonstrates that formalin-fixed tissues and their fixing solutions can be used for cocaine analysis only if a short time period has passed since the fixation beginning. The rapid extraction process of cocaine into formalin and the concomitant hydrolysis to BE occurring in buffered formalin may prevent the identification of cocaine in both tissues and formalin solution already at 15-30 days after fixation. Moreover, the unpredictable extraction rate of both analytes, along with the hydrolysis of cocaine into BE significantly affects tissue concentrations, thus complicating the interpretation of quantitative results.

Pharmacokinetics of disappearance of cocaine from hair after discontinuation of drug use.

UNLABELLED: Methods that employ detection of drugs of abuse in hair are important for monitoring compliance with drug abstinence. Understanding the mechanisms and timeline of drug disappearance from hair is critical for clinical and forensic application of hair testing. We aimed to evaluate the kinetics of disappearance of cocaine and its metabolite, benzoylecgonine (BE), from hair after discontinuation of drug use. METHODS: The Motherisk laboratory at the Hospital for Sick Children in Toronto routinely receives hair samples for toxicology analysis. Cocaine and BE hair results were obtained from the Motherisk Database for calculation of half-life of these compounds in hair. Subjects were included in the study if they had gradually decreasing concentrations of cocaine and/or BE in sequential hair samples, with higher levels in the 1-3 cm distal segments (i.e. earlier in time) and low or non-measurable levels in the segment closest to the scalp (i.e. closer to the date of sampling). Elimination half-life of cocaine and BE in hair was calculated using standard kinetics calculations. The study was anonymous, and received ethics approval by the Ethics Review Board of our institution. RESULTS: 137 subjects met the inclusion criteria for the study. The median half-life of cocaine in hair was 1.5 months (95% CI 1.2-1.8) in females and 1.5 months (95% CI 1.1-1.8) in males. The median half-life of BE was 1.5 months (95% CI 1.1-2) in females and 1.5 months (95% CI 0.8-1.8) in males. Half lives of cocaine or BE were not statistically different between males and females (Mann-Whitney U-test; P=0.93 for cocaine, P=0.99 for BE). Half lives of cocaine and BE were strongly correlated (Spearman rank rho=0.73; P<0.001). CONCLUSION: Cocaine and BE could be detected in hair of former drug users for several months after abstinence. The calculated half-life of over 1 month for cocaine implies that, assuming first order elimination, approximately 3-4 months have to pass for hair testing to become negative in the segment proximal to the scalp. This finding should be incorporated in interpreting compliance with abstinence of former drug users, and suggests that caution has to be exerted when evaluating potential breaches of abstinence.

Brain biomarkers for identifying excited delirium as a cause of sudden death.

Excited delirium (ED) syndrome is a serious medical condition associated with acute onset of agitated violent behavior that often culminates in a sudden unexplained death. While the contribution of restraint, struggle and the use of conductive energy devices (CED) to the cause and manner of death raise controversy, a CNS dysfunction of dopamine signaling may underlie the delirium and fatal autonomic dysfunction. We conducted a mortality review for a case series of ninety excited delirium deaths and present results on the association of a 2-protein biomarker signature. We conducted quantitative analyses of the dopamine transporter and heat shock protein 70 validated for specificity and degree of interindividual variation. Incident circumstances, force measures, autopsy and toxicology results were determined for all subjects. A majority of the victims in this case series tested positive for cocaine in blood and brain, although four had no licit or illicit drugs or alcohol measured at autopsy. Mean core body temperature where recorded was 40.7 degrees C. The expression of the heat shock protein HSPA1B transcript was elevated 1.8-4-fold in postmortem brain. The elevation of Hsp70 in autopsy brain specimens confirms that hyperthermia is an associated symptom and often a harbinger of death in these cases. Dopamine transporter levels were below the range of values measured in age-matched controls, providing pathologic evidence for increased risk of chaotic dopamine signaling in excited delirium. When combined with descriptions of the decedents' behavior prior to death, a 2-protein biomarker signature can serve as a reliable forensic tool for identifying the excited delirium syndrome at autopsy.

Hair testing is superior to urine to disclose cocaine consumption in driver's licence regranting.

In driver licence regranting, subjects with a history of cocaine use are requested to undergo laboratory testing to verify both current and past abstinence from the drug. Identification of cocaine use based only on urinalysis may miss some cases because of the short elimination half-life of the drug. Moreover, many abusers know how to time their cocaine consumption in such a way that they can "beat" the urinalysis, having a series of negative urine tests. We report on the use of hair testing to disclose sporadic cocaine consumption in seven subjects attending the Local Medical Commission to reobtain driver licence, with constant negative urinalysis. Even with one or two weekly negative urine screens along several months, all the subjects were positive using hair testing for cocaine and benzoylecgonine, above the internationally recommended limit of quantification: 0.5 ng/mg and 0.05 ng/mg for cocaine and benzoylecgonine, respectively (concentration range for cocaine: 0.51-2.23 ng/mg hair; concentration range for benzoylecgonine: 0.08-1.70 ng/mg hair). The obtained results support strongly the use of hair testing for cocaine in drug addicts and occasional abusers applying for regranting of driver licence in order to minimize social risk behaviours.

Death of a female cocaine user due to the serotonin syndrome following moclobemide-venlafaxine overdose.

To our knowledge, the majority of evidence supporting the relationship between the serotonin syndrome and medications that effect 5HT is based on case reports. The justification for taking up this subject has been a fatal outcome of a 21 year-old female following an administration of toxic doses of moclobemide (MAOI) and venlafaxine (SNRI). As a result of complex toxicological investigations including antemortem and postmortem material, antemortem clinical observations and postmortem examinations, the cause of death was identified as overdose with antidepressants--moclobemide and venlafaxine--in the mechanism of the clinically fully developed severe toxic serotonin syndrome. The analysis of a hair strand collected from the victim documented the use of the above-mentioned drugs simultaneously with cocaine in the period of at least 20 months preceding death. The fact is a matter of considerable interest in view of the employed pharmacotherapy, giving rise to suspicion that the woman had not developed the serotonin syndrome during the almost 2-year antemortem period until she took toxic doses of both medications.

Cocaine and opiate concentrations in hair from subjects in a heroin maintenance program in comparison to a methadone substituted group.

One month before (T-1) and 12 months after (T12) controlled i.v. administration of pharmaceutical heroin-HCl (10-100 mg/day) in the context of a heroin maintenance program (HMP), concentrations of opiates and cocaine as well as its metabolites were determined in head hair (n = 46) using a validated gas chromatographic-mass spectrometric method. In addition, a patient collective of a methadone maintenance program (MMP, daily doses 15-260 mg) was examined (n = 35). The incidence of additional cocaine consumption decreased in both groups during the study period (T-1 to T12): in HMP from 64.6% to 45.8% and in MMP from 71.4% to 60.0%. A significant reduction of cocaine consumption was defined as an at least 30% reduction of analyte concentrations in hair (Deltac > 30%). Accordingly, in HMP, a decrease in 45.8% of initially (T-1) cocaine-positive patients was determined; in MMP, the reduction was 48.6%. In 22.9% of HMP and 37.1% of MMP, an increase of cocaine concentrations was detected. Codeine and acetylcodeine were found in 50.0% and 43.5% (T-1) and 13.0% and 10.9% (T12) of the samples of the HMP, as well as in 45.7% and 25.7% (T-1) and 17.1% and 5.7% (T12) in MMP, respectively. The missing of acetylcodeine, in particular at T-1, questions its applicability as a characteristic marker of a preceding consumption of illicit heroin in hair analysis.