Oral fluid for workplace drug testing: Laboratory implementation

Abuse of Licit and Illicit Psychoactive Substances in the Workplace: Medical, Toxicological, and Forensic Aspects

About one-third of adult life is spent in the workplace. The use of psychoactive substances is a major preventable cause of morbidity and mortality. The consumption of psychoactive substances during or outside working hours greatly increases the frequency and severity of labor accidents, as well as the workers’ poor general state of health and productivity, implying higher costs for enterprises. It is the responsibility of organizations to ensure the safety and health of their workers. These cannot be limited to traditional routine clinical exams, as other aspects also have an impact on health. Thus, prevention and intervention in the consumption of psychoactive substances (e.g., ethanol, opioids, central nervous system stimulants or depressants, hallucinogens, Cannabis derivatives, dissociative substances, and inhalants) in labor activity should be considered as an investment of organizations and not as a cost, in view of the professional, personal, and family advantages for workers and employers, with a potential impact on productivity, security, health, and quality of life at work. Despite the extensive literature on the subject, each article generally focuses on one or another aspect of a very specific nature, not tackling the problem in a holistic way by confronting clinical, safety, and legal issues. This article presents a reflection on the legal, laboratorial, clinical, ethical, forensic, and safety concerns related to the consumption of psychoactive substances in the workplace, and can be a cross-cutting contribution to occupational medicine, forensic medicine, and insurance medicine, as well as for entrepreneurs, lawyers, judges, workers, and technicians from the public and private sectors that develop projects in this area. This discussion is based on general principles established internationally and highlights the role of the occupational healthcare system and other decision-making actors in the prevention and supervision of workplace psychoactive consumption.

The utility of delta 9-tetrahydrocannabinol (THC) measures obtained from oral fluid samples in traffic safety

Objective: Blood and/or urine are typical drug detection matrices used by law enforcement. There are some concerns about using oral fluid (OF) in the identification of drivers potentially impaired by cannabis, particularly regarding their accuracy when compared to blood. The study objectives were to (1) examine the accuracy of predicting delta 9-tetrahydrocannabinol (THC) in blood from THC measured in OF and (2) examine factors influencing prediction accuracy. Methods: Using data from the 2007 and 2013-2014 National Roadside Survey (NRS) of Alcohol and Drug Use, 7,517 drivers with known laboratory results in both OF and blood were included in this study. OF samples were collected using the Quantisal® device and analyzed at the same private laboratory in both the 2007 and 2013-2014 NRS. The Quantisal device has consistently shown to collect 1 mL ±10%. Descriptive statistical analyses were used to examine and compare the distribution of THC concentrations in OF and blood. A hurdle model was applied to examine factors influencing the accuracy of the THC_blood predictions based on THC_OF while accounting for the decisions of cannabis consumption. We estimated the number of true positives (TPs), false positives (FPs), true negatives (TNs), false negatives (FNs), sensitivity, specificity, and positive predicted value (PPV). Results: This study found that THC measured in OF (THC_OF) is a good predictor of THC measured in blood (THC_blood), in particular when THC_OF > 0 ng/mL is used to predict being positive for THC_blood (THC_blood > 0 ng/mL). However, as blood and OF concentrations depart from 0 ng/mL, the proportion of TPs (sensitivity) decreases, which might be a concern for law enforcement. The likelihood of accurately predicting THC_blood from THC_OF is lower for drivers who were simultaneously using cannabis and other drugs. Conclusions: The findings of this study are based on THC measures obtained in a laboratory, which may not be the same as those conducted by police using point-of-care devices. However, this study is unique due to its large sample of drivers obtained in similar roadside locations and times to actual law enforcement activities. Though a positive THC_OF may assist law enforcement in probable cause for a blood draw, efforts to develop reliable methods to detect drug impairment based on OF should continue.

Urine and oral fluid drug testing in support of pain management

In recent years, the abuse of opioid drugs has resulted in greater prevalence of addiction, overdose, and deaths attributable to opioid abuse. The epidemic of opioid abuse has prompted professional and government agencies to issue practice guidelines for prescribing opioids to manage chronic pain. An important tool available to providers is the drug test for use in the initial assessment of patients for possible opioid therapy, subsequent monitoring of compliance, and documentation of suspected aberrant drug behaviors. This review discusses the issues that most affect the clinical utility of drug testing in chronic pain management with opioid therapy. It focuses on the two most commonly used specimen matrices in drug testing: urine and oral fluid. The advantages and disadvantages of urine and oral fluid in the entire testing process, from specimen collection and analytical methodologies to result interpretation are reviewed. The analytical sensitivity and specificity limitations of immunoassays used for testing are examined in detail to draw attention to how these shortcomings can affect result interpretation and influence clinical decision-making in pain management. The need for specific identification and quantitative measurement of the drugs and metabolites present to investigate suspected aberrant drug behavior or unexpected positive results is analyzed. Also presented are recent developments in optimization of test menus and testing strategies, such as the modification of the standard screen and reflexed-confirmation testing model by eliminating some of the initial immunoassay-based tests and proceeding directly to definitive testing by mass spectrometry assays.

Oral fluid drug analysis in the age of new psychoactive substances

Oral fluid has become an important matrix for drugs of abuse analysis. These days the applicability is challenged by the fact that an increasing number of new psychoactive drugs are coming on the market. Synthetic cannabinoids and synthetic cathinones have been the main drug classes, but the diversity is increasing and other drugs like piperazines, phenethylamines, tryptamines, designer opioids and designer benzodiazepines are becoming more prevalent. Many of the substances are very potent, and low doses ingested will lead to low concentrations in biological media, including oral fluid. This review will highlight the phenomenon of new psychoactive substances and review methods for oral fluid drug testing analysis using on-site tests, immunoassays and chromatographic methods.

Current knowledge on cannabinoids in oral fluid

Oral fluid (OF) is a new biological matrix for clinical and forensic drug testing, offering non-invasive and directly observable sample collection reducing adulteration potential, ease of multiple sample collections, lower biohazard risk during collection, recent exposure identification, and stronger correlation with blood than urine concentrations. Because cannabinoids are usually the most prevalent analytes in illicit drug testing, application of OF drug testing requires sufficient scientific data to support sensitive and specific OF cannabinoid detection. This review presents current knowledge of OF cannabinoids, evaluating pharmacokinetic properties, detection windows, and correlation with other biological matrices and impairment from field applications and controlled drug administration studies. In addition, onsite screening technologies, confirmatory analytical methods, drug stability, and effects of sample collection procedure, adulterants, and passive environmental exposure are reviewed. Delta-9-tetrahydrocannabinol OF concentrations could be >1000 µg/L shortly after smoking, whereas minor cannabinoids are detected at 10-fold and metabolites at 1000-fold lower concentrations. OF research over the past decade demonstrated that appropriate interpretation of test results requires a comprehensive understanding of distinct elimination profiles and detection windows for different cannabinoids, which are influenced by administration route, dose, and drug use history. Thus, each drug testing program should establish cut-off criteria, collection/analysis procedures, and storage conditions tailored to its purposes. Building a scientific basis for OF testing is ongoing, with continuing OF cannabinoids research on passive environmental exposure, drug use history, donor physiological conditions, and oral cavity metabolism needed to better understand mechanisms of cannabinoid OF disposition and expand OF drug testing applicability. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Comparing drug detection in oral fluid and blood: data from a national sample of nighttime drivers

OBJECTIVE

The National Roadside Survey is a study undertaken in the United States to determine the prevalence of alcohol and drugs in randomly selected drivers. Following the success of a 2006 pilot study, the 2007 survey incorporated, for the first time, the collection of biological specimens for drug analysis. This article compares the results obtained from blinded analyses of pairs of oral fluid and blood samples obtained from the same subject.

METHODS

During the 2007 survey, more than 7000 nighttime drivers were randomly stopped and surveyed for their self-reported drug use and were requested to donate an oral fluid specimen using the Quantisal (Immunalysis Corporation, Pomona, CA) device and a blood sample. Overall, 5869 oral fluid specimens were collected from nighttime drivers with 3236 corresponding blood samples.

RESULTS

Biological specimens were analyzed for a wide range of drugs. At nighttime, 14.4 percent of the drivers were positive for drugs in oral fluid, with just over half of those having marijuana present (7.6%). Of the 3236 pairs of specimens, 2676 were negative for all drugs, and 326 matched pairs of samples were both positive, out of which 247 (75.8%) were an exact match for all drug classes and 70 (21.5%) were positive for at least one common drug class.

CONCLUSIONS

Oral fluid and blood samples provided very similar information regarding recent drug intake by randomly tested drivers and oral fluid yielded a higher detection rate for one drug (cocaine) than blood. Oral fluid can be considered a reliable alternative to blood as a matrix for drug testing.

Screening of synthetic cannabinoids in preserved oral fluid by UPLC–MS/MS

Background: The abuse of a rapidly changing range of synthetic cannabinoids is increasing worldwide. Oral fluid, which contains the parent compounds and is easily collected, could be a good alternative medium for drug screening for synthetic cannabinoids. Results: A method for screening of 18 synthetic cannabinoids in preserved oral fluid collected with the Intercept® collection device, using UPLC–MS/MS, was validated. Limits of quantification ranged from 0.2 to 2 ng/ml in oral fluid. In several real cases, AM-2201 and/or JWH-018 were found. Conclusion: The presented method allowed rapid and sensitive screening of synthetic cannabinoids in preserved oral fluid collected with the Intercept collection device.

Oral fluid cannabinoids in chronic cannabis smokers during oral δ9-tetrahydrocannabinol therapy and smoked cannabis challenge

BACKGROUND

Oral Δ(9)-tetrahydrocannabinol (THC) is effective for attenuating cannabis withdrawal and may benefit treatment of cannabis use disorders. Oral fluid (OF) cannabinoid testing, increasing in forensic and workplace settings, could be valuable for monitoring during cannabis treatment.

METHODS

Eleven cannabis smokers resided on a closed research unit for 51 days and received daily 0, 30, 60, and 120 mg of oral THC in divided doses for 5 days. There was a 5-puff smoked cannabis challenge on the fifth day. Each medication session was separated by 9 days of ad libitum cannabis smoking. OF was collected the evening before and throughout oral THC sessions and analyzed by 2-dimensional GC-MS for THC, cannabidiol (CBD), cannabinol (CBN), 11-hydroxy-THC (11-OH-THC), and 11-nor-9-carboxy-THC (THCCOOH).

RESULTS

During all oral THC administrations, THC OF concentrations decreased to ≤ 78.2, 33.2, and 1.4 μg/L by 24, 48, and 72 h, respectively. CBN also decreased over time, with concentrations 10-fold lower than THC, with none detected beyond 69 h. CBD and 11-OH-THC were rarely detected, only within 19 and 1.6 h after smoking, respectively. THCCOOH OF concentrations were dose dependent and increased over time during 120-mg THC dosing. After cannabis smoking, THC, CBN, and THCCOOH concentrations showed a significant dose effect and decreased significantly over time.

CONCLUSIONS

Oral THC dosing significantly affected OF THCCOOH but minimally contributed to THC OF concentrations; prior ad libitum smoking was the primary source of THC, CBD, and CBN. Higher cannabinoid concentrations following active oral THC administrations vs placebo suggest a compensatory effect of THC tolerance on smoking topography.

Continuous, quantitative monitoring of roxithromycin in human saliva by flow injection chemiluminescence analysis

Human saliva quantitative monitoring of roxithromycin (ROX) at picomolar-level by flow injection (FI) chemiluminescence (CL) analysis is described for the first time, to our knowledge. Monitoring was based on the CL intensity from luminol-BSA reaction, which can be quenched in the presence of ROX, with the decreasing CL intensity linearly proportional to the logarithm of the ROX concentration, ranging from 0.6 to 1000 pmol·L(-1). The detection limit of the proposed method for the determination of ROX was as low as 0.2 pmol·L(-1) (3σ), and the relative standard deviations were less than 4.0% (n = 7). A complete analytical process, including sampling and washing for ROX determination, conducted at a flow rate of 2.0 mL·min(-1), was performed completely within 30 s, yielding a sample efficiency of 120 h(-1). The proposed method was successfully applied to the determination of ROX in human saliva and serum samples with recoveries from 90.9% to 110.1%. The continuous monitoring of ROX in human saliva after oral intake showed that the total elimination ratio was 87.1% during 24 h, and the pharmacokinetic parameters were 0.97 ± 0.18 h(-1) for the absorption rate constant K(a), 0.082 ± 0.010 h(-1) for the elimination rate constant K(e), and 8.56 ± 1.11 h for the elimination half-life time t(1/2). It was also found that ROX in human saliva and urine simultaneously reached the maximum at 2 h with the concentration correlate ratio of 0.97.

Cannabinoids and metabolites in expectorated oral fluid following controlled smoked cannabis

BACKGROUND

∆(9)-Tetrahydrocannabinol (THC) in oral fluid (OF) implies cannabis intake, but eliminating passive exposure and improving interpretation of test results requires additional research.

METHODS

Ten adult cannabis users smoked ad libitum one 6.8% THC cigarette. Expectorated OF was collected for up to 22 h, and analyzed within 24h of collection. THC, 11-nor-9-carboxy-THC (THCCOOH), cannabidiol, and cannabinol were quantified by 2-dimensional-GCMS.

RESULTS

Eighty specimens were analyzed; 6 could not be collected due to dry mouth. THC was quantifiable in 95.2%, cannabidiol in 69.3%, cannabinol in 62.3%, and THCCOOH in 94.7% of specimens. Highest THC, cannabidiol, and cannabinol concentrations were 22370, 1000, and 1964 μg/l, respectively, 0.25 h after the start of smoking; THCCOOH peaked within 2h (up to 560 ng/l). Concentrations 6h after smoking were THC (0.9-90.4 μg/l) and THCCOOH (17.0-151 ng/l) (8 of 9 positive for both); only 4 were positive for cannabidiol (0.5-2.4 μg/l) and cannabinol (1.0-3.0 μg/l). By 22 h, there were 4 THC (0.4-10.3 μg/l), 5 THCCOOH (6.0-24.0 ng/l), 1 cannabidiol (0.3 μg/l), and no cannabinol positive specimens.

CONCLUSIONS

THCCOOH in OF suggests no passive contamination, and CBD and CBN suggest recent cannabis smoking. Seventeen alternative cutoffs were evaluated to meet the needs of different drug testing programs.