Drug Screening of 49 Compounds by Liquid Chromatography-Tandem Mass Spectrometry in Saliva

In recent years, the use of oral fluid as a testing matrix for drug analysis has become increasingly popular due to its benefits, such as a possibility for direct observation of a sample collection and, thus, a lower risk of adulteration. To address this trend, we have developed a quantitative LC-MS/MS method that can simultaneously analyze 49 commonly prescribed compounds in oral fluid. The assay is performed on an AB Sciex 4500 electrospray ionization mass spectrometer in multiple reaction monitoring mode.

Oral Cavity Fluid as an Alternative Postmortem Matrix: Comparison to Simultaneously Collected Blood and Urine Specimens

ABSTRACT

In postmortem toxicology analysis, a variety of specimens consisting of fluids and tissues are often collected, each with an intrinsic value. Oral cavity fluid (OCF) is emerging as an alternative matrix in forensic toxicology for contributing to a diagnosis in postmortem cases; especially when blood is limited or not available. The aim of this study was to assess the analytical results obtained from OCF and compare them with blood, urine, and other traditional matrices collected from the same postmortem subjects. Of the 62 decedents studied (including 1 stillborn, 1 charred, and 3 decomposed subjects), 56 had quantifiable drugs and metabolites data in the OCF, blood, and urine. Notable findings were benzoylecgonine (24 cases), ethyl sulfate (23 cases), acetaminophen (21 cases), morphine (21 cases), naloxone (21 cases), gabapentin (20 cases), fentanyl (17 cases), and 6-acetylmorphine (15 cases), which were detected more frequently in OCF than in blood (heart, femoral, or body cavity) or urine. This study suggests that OCF is a suitable matrix for detecting and quantifying analytes in postmortem subjects compared with traditional matrices, particularly when other matrices are limited or difficult to collect because of body condition or putrefaction.

Advances in fentanyl testing

Fentanyl is a synthetic opioid that was approved by the FDA in the late 1960s. In the decades since, non-prescription use of fentanyl, its analogs, and structurally unrelated novel synthetic opioids (NSO) has become a worsening public health crisis. There is a clear need for accessible testing for these substances in biological specimens and in apprehended drugs. Immunoassays for fentanyl in urine are available but their performance is restricted to facilities that hold moderate complexity laboratory licenses. Immunoassays for other matrices such as oral fluid (OF), blood, and meconium have been developed but are not widely available. Point of care tests (POCT), such as lateral flow immunoassays or fentanyl test strips (FTS), are widely available but not approved by the FDA for clinical use. All immunoassays are vulnerable to false positive and false negative results. Immunoassays may or may not be able to detect fentanyl analogs and NSOs. Mass spectrometry (MS) can accurately and reliably measure fentanyl and its major metabolite norfentanyl in urine and oral fluid. MS is available at reference laboratories and large hospitals. Liquid chromatography paired with tandem mass spectrometry (LC-MS/MS) is the most widely used method and has outstanding specificity and sensitivity for fentanyl and norfentanyl. When compared to immunoassays, MS is more expensive, requires more technical skill, and takes longer to result. Newer mass spectrometry methods can measure fentanyl analogs and NSO. Both mass spectrometry assays and immunoassays [in the form of fentanyl test strips (FTS)] have potential use in harm reduction programs.

Salivary Biomarkers of Anti-Epileptic Drugs: A Narrative Review

Saliva is a biofluid that reflects general health and that can be collected in order to evaluate and determine various pathologies and treatments. Biomarker analysis through saliva sampling is an emerging method of accurately screening and diagnosing diseases. Anti-epileptic drugs (AEDs) are prescribed generally in seizure treatment. The dose-response relationship of AEDs is influenced by numerous factors and varies from patient to patient, hence the need for the careful supervision of drug intake. The therapeutic drug monitoring (TDM) of AEDs was traditionally performed through repeated blood withdrawals. Saliva sampling in order to determine and monitor AEDs is a novel, fast, low-cost and non-invasive approach. This narrative review focuses on the characteristics of various AEDs and the possibility of determining active plasma concentrations from saliva samples. Additionally, this study aims to highlight the significant correlations between AED blood, urine and oral fluid levels and the applicability of saliva TDM for AEDs. The study also focuses on emphasizing the applicability of saliva sampling for epileptic patients.

Randomly controlled drivers using minimally invasive sampling: assessment of drug prevalence in Western Switzerland over two time periods

BACKGROUND

According to the World Health Organization, road traffic injuries lead to 1.3 million deaths each year and represent the leading cause of death for young adults under 30 years old. The use of psychoactive substances, including alcohol, drugs and pharmaceuticals, is a well-known risk factor for road traffic injuries. Our study aims to assess the prevalence of substances consumed by drivers in western Switzerland. Such studies are pivotal to improving prevention and developing public awareness campaigns.

METHODS

To assess the prevalence of psychoactive substances among drivers, roadside controls were performed in collaboration with local police, using their classical sampling procedures to detect drivers under the influence of drugs or alcohol over two time periods (P1: 2006-2008, P2: 2017-2020). When impaired driving was not suspected by the police, minimally invasive sampling strategies (i.e., oral fluids during P1 and dried blood spots during P2) were performed on volunteer drivers after a road safety survey. A posteriori analyses and statistical interpretation were then performed.

RESULTS

Among the 1605 drivers included in the study, 1048 volunteers provided an oral fluid sample, while 299 provided a dried blood spot sample. The percentage of drivers testing positive for at least one substance that can impact driving abilities was stable over time, with a rate of 10.5% positivity measured over both periods. Considering the different categories of substances, a slight variation was observed between both periods, with 7.6 and 6.3% of pharmaceuticals and 3.6 and 4.9% of illicit drugs for P1 and P2, respectively. Regarding the consumption of illicit drugs, the highest percentage of positivity was measured in biological fluids of drivers under the age of 35, during nights and week-ends, periods which are considered particularly prone to fatal accidents for this age group. Disturbingly, the road safety survey highlighted that drivers' perception of the risk of getting positively controlled while driving after drug consumption is low (3.3 on a 1-to-10 scale, N = 299).

CONCLUSION

The number of positive cases measured in voluntary drivers who passed the preliminary police check demonstrates the importance of systematic biofluid sampling strategies regarding driving under the influence of psychoactive substances. Although the number of fatal road accidents globally has decreased over time, the results of this study reveal the need for both better prevention and deterrent processes that could potentially reduce the risk of fatal road accidents associated with drug consumption.

Superhydrophobic 3D-Assembled Metallic Nanoparticles for Trace Chemical Enrichment in SERS Sensing

The performance of surface-enhanced Raman spectroscopy (SERS) is determined by the interaction between highly diluted analytes and boosted localized electromagnetic fields in nanovolumes. Although superhydrophobic surfaces are developed for analyte enrichment, i.e., to concentrate and transfer analytes toward a specific position, it is still challenging to realize reproducible, uniform, and sensitive superhydrophobic SERS substrates over large scales, representing a major barrier for practical sensing applications. To overcome this challenge, a superhydrophobic SERS chip that combines 3D-assembled gold nanoparticles on nanoporous substrates is proposed, for a strong localized field, with superhydrophobic surface treatment for analyte enrichment. Intriguingly, by concentrating droplets in the volume of 40 µL, the sensitivity of 1 nm is demonstrated using 1,2-bis(4-pyridyl)-ethylene molecules. In addition, this unique chip demonstrates a relative standard deviation (RSD) of 2.2% in chip-to-chip reproducibility for detection of fentanyl at 1 µg mL^-1 concentration, revealing its potential for quantitative sensing of chemicals and drugs. Furthermore, the trace analysis of fentanyl and fentanyl-heroin mixture in human saliva is realized after a simple pretreatment process. This superhydrophobic chip paves the way toward on-site and real-time drug sensing to tackle many societal issues like drug abuse and the opioid crisis.

Recent Update on Pretreatment and Analysis Methods of Buprenorphine in Different Matrix

Buprenorphine is one of the most commonly used pain-killing drugs due to its lengthy duration of action and high potency. However, excessive usage of buprenorphine can be harmful to one's health and prolonged use might result in addiction. Additionally, an increasing number of cases have been documented involving the illegal use of buprenorphine. Therefore, a variety of effective and reliable methods for pretreatment and determination of buprenorphine and its main metabolite norbuprenorphine have been established. This review aims to update the current state of pretreatment and detection techniques for buprenorphine and norbuprenorphine from January 2010 to March 2022. Pretreatment methods include several traditional extraction methods, solid-phase extraction, QuECHERS, various micro-extraction techniques, etc. while analytical methods include LC-MS, LC coupled with other detectors, GC-MS, capillary electrophoresis, electrochemical sensors, etc. The pros and cons of various techniques were compared and summarized, and the prospects were provided. HIGHLIGHTSProgress in pretreatment and detection methods for buprenorphine is demonstrated.Pros and cons of different pretreatment and analysis methods are compared.New materials (such as nanomaterials and magnetic materials) used in buprenorphine pretreatment are summarized.Newly emerged environmental-friendly methods are discussed.

Correlation between oral fluid and blood THC concentration: A systematic review and discussion of policy implications

Cannabis is the second most commonly used impairing substance by drivers, after alcohol. As more countries legalize cannabis, there is concern that cannabis-impaired driving will increase. In many countries, police use roadside devices to test for oral fluid THC (the primary psychotropic component in cannabis) to identify drivers who used cannabis; including in countries with non-zero per se limits for THC in blood. This practice is questioned as previous research demonstrates a poor correlation between oral fluid and blood THC concentrations at the individual level. We conducted a meta-analysis to identify all research that compared oral fluid with blood THC levels. We obtained individual-level data from study authors and analyzed pooled individual-level data to calculate sensitivity and specificity of oral fluid THC (at various cut-off values) to detect blood THC above different concentration limits. Finally, we explored practical implications of using oral fluid THC in an enforcement context. Our review found THC concentrations measured in over 18,000 paired samples of oral fluid and blood. We found a good correlation between the presence of THC in oral fluid and presence of THC in blood (sensitivity = 71.2%, specificity = 97.7%). However oral fluid THC, at commonly used cut-off values, is less sensitive and less specific when used as a biomarker to detect people with blood THC concentrations above commonly used per se limits (such as 5 ng/mL). As such, there will be a large number of "false positive" tests if oral fluid THC testing were used as a biomarker for "illegal" THC concentrations in randomly selected drivers. We argue that the adverse implications of false positive oral fluid THC tests in this context outweigh the possible road safety benefits and we recommend against oral fluid THC screening in randomly selected drivers in countries with non-zero per se limits for blood THC. In contrast, oral fluid THC tests appear to be useful for investigating "high-risk" drivers who come to police attention because of evidence of impairment.

Review of LC techniques for determination of methadone and its metabolite in the biological samples

Methadone (MTD) is a synthetic analgesic drug used for treating opioid dependence and effectively used clinically for patients with severe pain. The abuse of MTD may lead to poisoning, disorder in the central nervous system and even death. The regular monitoring of MTD in biological matrices including serum, plasma and urine samples is an effective way to control abuse of MTD. In this manner, the selection of analytical monitoring of MTD in biological matrices is of paramount importance. This study was conducted to review high-performance liquid chromatography (HPLC) techniques carried out on MTD and its main metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) in the biological samples during 2015-June 2021.

Comparison of Oral Fluid and Urine for Detection of Fentanyl Use Using Liquid Chromatography with Tandem Mass Spectrometry

BACKGROUND

We compared oral fluid (OF) and urine (UR) for detection of fentanyl (FEN) use in addiction medicine-psychiatry (AMP) clinics.

METHODS

We measured FEN and norfentanyl (NRFEN) in UR with a limit of detection (LOD) of 2.0 µg/L and FEN in OF with an LOD of 0.5 µg/L by LC-MS/MS in 311 paired samples and compared the 2 matrices when higher OF and UR LODs were used.

RESULTS

Urine (UR) detected more FEN use than OF using a LOD of 2.0 µg/L and 0.5 µg/L, respectively. FEN and/or NRFEN were detected in 44 and 59 UR specimens, respectively, and FEN in 46 OF specimens (43 OF+UR+, 3 OF+UR-, 16 OF-UR+, and 249 OF-UR-). In UR there were no instances with FEN positive and NORFEN negative. UR creatinine was <20 mg/dL in the 3 OF+UR- specimen pairs. The median OF/UR analyte concentration ratios in positive sample pairs were 0.23 for OF FEN/UR FEN and 0.02 for OF FEN/UR NRFEN.

CONCLUSIONS

We demonstrate that UR detects more FEN use than OF in an AMP setting when UR FEN and UR NORFEN LODs of 2.0 µg/L are used. OF is less sensitive than UR in detecting FEN use, but is still valuable for cases with low UR creatinine and/or suspected adulteration or substitution of UR. The UR vs OF comparison statistics are greatly impacted by even minimal adjustments of the LOD.

Recommendations for Toxicological Investigation of Drug-Impaired Driving and Motor Vehicle Fatalities-2021 Update

This report describes updates to the National Safety Council’s Alcohol, Drugs and Impairment Division’s recommendations for drug testing in driving under the influence of drug (DUID) cases and motor vehicle fatalities. The updates are based on a survey of drug testing practices in laboratories in the USA and Canada, a comprehensive review of the prior recommendations and data and research on drugs most frequently detected in DUID cases. A consensus meeting was held with representative forensic science practitioners and the authors of this report to update recommendations. No changes were made to the Tier I scope; however, there were changes to cutoffs of some analytes for blood, urine and oral fluid. Due to increased prevalence in DUID cases, trazodone and difluoroethane were added to the Tier II scope. For clarification, Tier I cutoffs reflect free concentrations, and hydrolysis is recommended but not required. The consensus panel concluded that urine is an inferior matrix to blood and oral fluid as it may represent historical use or exposure unrelated to observed impairment; therefore, future iterations of these recommendations will not include urine as a recommended matrix. Laboratories currently testing urine should work with traffic safety partners to encourage the use of blood and oral fluid as more appropriate specimens and adjust their capabilities to provide that testing.

Evaluation of the diagnostic performance of an oral fluid screening test device for substance abuse at traffic controls

INTRODUCTION

The aim of this study was to evaluate the analytical performance of the Kite Biotechnology Oral fluid (OF) screening test device, which is used for roadside screening of cannabis, opiates, amphetamines, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), cocaine and benzodiazepines by comparing samples with matched plasma samples, analysed via liquid chromatography-tandem mass spectrometry (LC-MS/MS) for confirmation.

METHODS

OF and plasma samples were obtained simultaneously from a total of 100 subjects. OF samples were analysed by OF screening test based on immunochromatography. The OF screening test cut-off values were 50 ng/mL for amphetamines (d-amphetamine) and methamphetamine/MDMA (d-methamphetamine), 30 ng/mL for cocaine (benzoylecgonine), 40 ng/mL for opiates (morphine), 20 ng/mL for benzodiazepines (nordazepam), and 25 ng/mL for cannabis (Δ⁹-tetrahydrocannabinol). LC-MS/MS method validation was performed according to the CLSI C62-A recommendations with the following parameters: matrix effect, lower limit of quantification (LLOQ), linearity, intra-day and inter-day precision and accuracy.

RESULTS

The overall specificity, accuracy and negative predictive values (NPV) were acceptable and met the DRUID standard of >80%. The OF screening test device showed good sensitivity for cocaine, amphetamines and opiates, whereas it indicated poor sensitivity for methamphetamine/MDMA (66.7%) and failed to detect cannabis and benzodiazepines.

CONCLUSION

The present study is the first report to evaluate the Kite Biotechnology OF screening test device. The diagnostic performance of the OF screening test device was acceptable for opiates, cocaine and amphetamines, but it was insufficient for methamphetamine/MDMA, benzodiazepines and cannabis because of sensitivity issues.

Kinetic profile of N,N-dimethyltryptamine and β-carbolines in saliva and serum after oral administration of ayahuasca in a religious context

Ayahuasca is a beverage obtained from Banisteriopsis caapi plus Psychotria viridis. B. caapi contains the β-carbolines harmine, harmaline, and tetrahydroharmine that are monoamine oxidase inhibitors and P. viridis contains N,N-dimethyltryptamine (DMT) that is responsible for the visionary effects of the beverage. Ayahuasca use is becoming a global phenomenon, and the recreational use of DMT and similar alkaloids has also increased in recent years; such uncontrolled use can lead to severe intoxications. In this investigation, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to study the kinetics of alkaloids over a 24 h period in saliva and serum of 14 volunteers who consumed ayahuasca twice a month in a religious context. We compared the area under the curve (AUC), maximum concentration (C_max ), time to reach C_max (T_max ), mean residence time (MRT), and half-life (t_1/2 ), as well as the serum/saliva ratios of these parameters. DMT and β-carboline concentrations (C_max ) and AUC were higher in saliva than in serum and the MRT was 1.5-3.0 times higher in serum. A generalized estimation equations (GEEs) model suggested that serum concentrations could be predicted by saliva concentrations, despite large individual variability in the saliva and serum alkaloid concentrations. The possibility of using saliva as a biological matrix to detect DMT, β-carbolines, and their derivatives is very interesting because it allows fast noninvasive sample collection and could be useful for detecting similar alkaloids used recreationally that have considerable potential for intoxication.

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.

A surface plasmon resonance immunoassay for the rapid analysis of methamphetamine in forensic oral fluid

Background

Current chromatographic methods applied for the forensic analysis of methamphetamine are costly, time‐consuming, and require complicated pretreatment procedures. Thus, the rapid detection of methamphetamine is a critical and unmet need. In this study, a surface plasmon resonance (SPR) system based on indirect inhibitive immunoassay was designed for the analysis of methamphetamine in forensic oral fluid samples.

Methods

For the inhibition immunoassay, the diluted oral fluid was mixed with methamphetamine antibody and then injected into the SPR sensor chip. The biosensor chip was constructed by covalently immobilizing of methamphetamine‐bovine serum albumin conjugate onto a carboxymethyl dextran surface at an optimized pH. The concentration of antibody was also optimized.

Results

The SPR biosensor showed good sensitivity with a limit of detection of 0.44 ng/mL and was comparable or lower than the pre‐existing methods. The method was finally tested using oral fluid samples from 20 suspected drug abusers in forensic cases, and it provided an acceptable recovery of 113.2%, indicating good anti‐interference capability of the SPR sensor.

Conclusion

The SPR biosensor was rapid, reproducible, and had a great potential approach for the forensic detection of methamphetamine.