Current knowledge on cannabinoids in oral fluid

Abstract

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 on 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, on-site 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 cutoff criteria, collection/analysis procedures, and storage conditions tailored to its purposes. Building a scientific basis for OF testing is on-going, 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.

Detection of tetrahydrocannabinol residues on hands by ion-mobility spectrometry (IMS). Correlation of IMS data with saliva analysis

“…Drug testing for cannabis abuse is based on monitoring THC and its metabolites, mainly 11-hydroxy-THC (THC-COOH) because of its long lifetime, or two other natural, non-psychoactive cannabinoids, cannabidiol and cannabinol, the concentration of which is relatively high in cannabis [7]. Different biological matrices have been used to determine cannabis abuse, including urine, blood, oral fluid, sweat, and hair [3].…”

Feasibility of a group cessation program for co-smokers of cannabis and tobacco

“…Because the use of NRT was only assessed at EOT, this correction could not be applied for the follow-up assessment. Cannabis abstinence was not analytically validated because of the lack of methods of salivary delta-9-tetrahydrocannabinol (THC) verification that are valid and applicable under the sampling and transport conditions [33]. Furthermore, the course instructors were strongly opposed to collecting urine THC samples.…”

Techniques and Technologies for The Bioanalysis of Sativex ® , Metabolites and Related Compounds

“…The window of detection in blood and oral fluid is extended when analyzing for the metabolites, as these appear later and persist for longer. However, recent research shows the length of time, the various cannabinoids and their metabolites remain is dependent on a number of factors and is highly variable between individuals [102]. Consequently, while a positive blood or oral fluid result may be indicative of recent use, determining a specific time of last use is not currently feasible.…”

“…Observing similar concentrations of THC and CBD in any biological matrix is a good indication of Sativex treatment since the formulation contains an almost equal amount of the two. However, this current distinction may become future science group Review Molnar & Fu irrelevant in the future as cannabis plants containing higher CBD content increase in popularity, and with the emergence of e-cigarettes containing high levels of CBD with respect to THC [102,112]. Sativex doses may also mask concurrent illicit use [37].…”

“…Plasma/whole blood Short window of detection for parent THC is useful for determining recent use and possible impairment Relatively high concentrations of THC-COOH allow for easier detection Specialist equipment and personnel required for sample collection Highly sensitive methods required to detect parent THC [27,39] Urine Longer window of detection is useful for long-term drug monitoring Cannabinoid concentrations are unaffected by route of exposure Simple to collect Longer window of detection can be problematic when interpreting a positive result Privacy concerns surrounding sample collection Prone to adulteration practices [20,49] Oral fluid Shortest window of detection for parent THC Simple, noninvasive collection methods Large variations in cannabinoid concentrations depending on route of exposure [102] Hair Longest window of detection is useful for determining historic use or exposure Simple, noninvasive collection Helpful as a complementary testing matrix to confirm positive results from other tests Difficulties in distinguishing between active use and passive exposure Varied growth rates prevent determination of specific time intervals Sensitive detection methods required for the low picogram concentrations present [77][78][79] future science group…”