Oral fluid testing for marijuana intoxication: enhancing objectivity for roadside DUI testing

Adverse Impact of Cannabis on Human Health

Cannabis, the most commonly used recreational drug, is illicit in many areas of the world. With increasing decriminalization and legalization, cannabis use is increasing in the United States and other countries. The adverse effects of cannabis are unclear because its status as a Schedule 1 drug in the United States restricts research. Despite a paucity of data, cannabis is commonly perceived as a benign or even beneficial drug. However, recent studies show that cannabis has adverse cardiovascular and pulmonary effects and is linked with malignancy. Moreover, case reports have shown an association between cannabis use and neuropsychiatric disorders. With growing availability, cannabis misuse by minors has led to increasing incidences of overdose and toxicity. Though difficult to detect, cannabis intoxication may be linked to impaired driving and motor vehicle accidents. Overall, cannabis use is on the rise, and adverse effects are becoming apparent in clinical data sets.

Blood and Oral Fluid Cannabinoid Profiles of Frequent and Occasional Cannabis Smokers

Increased prevalence of cannabis consumption and impaired driving are a growing public safety concern. Some states adopted per se driving laws, making it illegal to drive with more than a specified ∆9-tetrahydrocannabinol (THC) blood concentration of THC in a biological fluid (typically blood). Blood THC concentrations decrease significantly (~90%) with delays in specimen collection, suggesting use of alternative matrices, such as oral fluid (OF). We characterized 10 cannabinoids' concentrations, including THC metabolites, in blood and OF from 191 frequent and occasional users by LC-MS-MS for up to 6 h after ad libitum smoking. Subjects self-titrated when smoking placebo, 5.9 or 13.4% THC cannabis. Higher maximum blood THC concentrations (Cmax) were observed in individuals who received the 5.9% THC versus the 13.4% THC plant material. In blood, the Cmax of multiple analytes, including THC and its metabolites, were increased in frequent compared to occasional users, whereas there were no significant differences in OF Cmax. Blood THC remained detectable (≥5 ng/mL) at the final sample collection for 14% of individuals who smoked either the 5.9% or 13.4% THC cigarette, whereas 54% had detectable THC in OF when applying the same cutoff. Occasional and frequent cannabis users' profiles were compared, THC was detectable for significantly longer in blood and OF from frequent users. Detection rates between frequent and occasional users at multiple per se cutoffs showed larger differences in blood versus OF. Understanding cannabinoid profiles of frequent and occasional users and the subsequent impact on detectability with current drug per se driving limits is important to support forensic interpretations and the development of scientifically supported driving under the influence of cannabis laws.

Analysis of cannabinoids in conventional and alternative biological matrices by liquid chromatography: Applications and challenges

Cannabis is by far the most widely abused illicit drug globe wide. The analysis of its main psychoactive components in conventional and non-conventional biological matrices has recently gained a great attention in forensic toxicology. Literature states that its abuse causes neurocognitive impairment in the domains of attention and memory, possible macrostructural brain alterations and abnormalities of neural functioning. This suggests the necessity for the development of a sensitive and a reliable analytical method for the detection and quantification of cannabinoids in human biological specimens. In this review, we focus on a number of analytical methods that have, so far, been developed and validated, with particular attention to the new "golden standard" method of forensic analysis, liquid chromatography mass spectrometry or tandem mass spectrometry. In addition, this review provides an overview of the effective and selective methods used for the extraction and isolation of cannabinoids from (i) conventional matrices, such as blood, urine and oral fluid and (ii) alternative biological matrices, such as hair, cerumen and meconium.

Quantitation of Δ8-THC, Δ9-THC, Cannabidiol, and Ten Other Cannabinoids and Metabolites in Oral Fluid by HPLC-MS/MS

Quantitative analysis of Δ9-tetrahydrocannabinol (Δ9-THC) in oral fluid has gained increasing interest in clinical and forensic toxicology laboratories. New medicinal and/or recreational cannabinoid products require laboratories to distinguish different patterns of cannabinoid use. This study validated a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for 13 different cannabinoids, including (-)-trans-Δ8-tetrahydrocannabinol (Δ8-THC), (-)-trans-Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD), Δ9-tetrahydrocannabinolic acid-A (Δ9-THCA-A), cannabidiolic acid (CBDA), 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-Δ9-THC), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (Δ9-THCCOOH), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), cannabidiorcol (CBD-C1), cannabichromene (CBC), cannabinol (CBN) and cannabigerol (CBG) in oral fluid. Baseline separation was achieved in the entire quantitation range between Δ9-THC and its isomer Δ8-THC. The quantitation range of Δ9-THC, Δ8-THC, and CBD was from 0.1 ng/mL to 800 ng/mL. Two hundred human subject oral fluid samples were analyzed with this method after solid phase extraction (SPE). Among the 200 human subject oral fluid samples, all 13 cannabinoid analytes were confirmed in at least one sample. Δ8-THC was confirmed in 11 samples, with or without the present of Δ9-THC. A high concentration of 11-OH-Δ9-THC or Δ9-THCCOOH (>400 ng/mL) was confirmed in three samples. CBD, Δ9-THCA-A, THCV, CBN, and CBG were confirmed in 74, 39, 44, 107, and 112 of the 179 confirmed Δ9-THC positive samples, respectively. The quantitation of multiple cannabinoids and metabolites in oral fluid simultaneously provides valuable information for revealing cannabinoid consumption and interpreting cannabinoid-induced driving impairment.

Pharmacokinetics of Cannabis Brownies: A Controlled Examination of Δ9-Tetrahydrocannabinol and Metabolites in Blood and Oral Fluid of Healthy Adult Males and Females

Oral cannabis products (a.k.a. "edibles") have increased in popularity in recent years. Most prior controlled pharmacokinetic evaluations of cannabis have focused on smoked cannabis and included males who were frequent cannabis users. In this study, 17 healthy adults (8 females), with no cannabis use in at least the past 2 months, completed 4 double-blind outpatient sessions where they consumed cannabis brownies containing Δ9-tetrahydrocannabinol (THC) doses of 0, 10, 25 or 50 mg. Whole blood and oral fluid specimens were collected at baseline and for 8 h post-brownie ingestion. Enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-tandem mass spectrometry (LC-MS-MS) were used to measure THC and relevant metabolites. In whole blood, concentrations of THC and 11-hydroxy-THC (11-OH-THC) peaked 1.5-2 h after brownie consumption, decreased steadily thereafter, and typically returned to baseline within 8 h. Blood concentrations for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) and THCCOOH-glucuronide were higher than THC and 11-OH-THC and these metabolites were often still detected 8 h post-brownie consumption. Women displayed higher peak concentrations for THC and all metabolites in whole blood compared to men, at least partially owing to their lower body weight/body mass index. Detection of THC in oral fluid was immediate and appeared to reflect the degree of cannabis deposition in the oral cavity, not levels of THC circulating in the blood. THC concentrations were substantially higher in oral fluid than in blood; the opposite trend was observed for THCCOOH. Agreement between ELISA and LC-MS-MS results was high (i.e., over 90%) for blood THCCOOH and oral fluid THC but comparatively low for oral fluid THCCOOH (i.e., 67%). Following oral consumption of cannabis, THC was detected in blood much later, and at far lower peak concentrations, compared to what has been observed with inhaled cannabis. These results are important given the widespread use of toxicological testing to detect recent use of cannabis and/or to identify cannabis intoxication.