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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 blood concentration of ∆9-tetrahydrocannabinol (THC) in a biological fluid (typically blood). Blood THC concentrations decrease significantly (∼90%) with delays in specimen collection, suggesting the 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 liquid chromatography with tandem mass spectrometry 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 duration 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. [ABSTRACT FROM AUTHOR]

With advances in analytical technology and new research informing result interpretation, oral fluid (OF) testing has gained acceptance over the past decades as an alternative biological matrix for detecting drugs in forensic and clinical settings. OF testing offers simple, rapid, non-invasive, observed specimen collection. This article offers a review of the scientific literature covering analytical methods and interpretation published over the past two decades for amphetamines, cannabis, cocaine, opioids, and benzodiazepines. Several analytical methods have been published for individual drug classes and, increasingly, for multiple drug classes. The method of OF collection can have a significant impact on the resultant drug concentration. Drug concentrations for amphetamines, cannabis, cocaine, opioids, and benzodiazepines are reviewed in the context of the dosing condition and the collection method. Time of last detection is evaluated against several agencies' cutoffs, including the proposed Substance Abuse and Mental Health Services Administration, European Workplace Drug Testing Society and Driving Under the Influence of Drugs, Alcohol and Medicines cutoffs. A significant correlation was frequently observed between matrices (i.e. between OF and plasma or blood concentrations); however, high intra-subject and inter-subject variability precludes prediction of blood concentrations from OF concentrations. This article will assist individuals in understanding the relative merits and limitations of various methods of OF collection, analysis and interpretation. [ABSTRACT FROM AUTHOR]

Oral fluid (OF) is increasingly used for clinical, forensic and work- place drug testing as an alternative to urine. Uncertainties surround- ing OF collection device performance, drug stability and testing reproducibility may be partially responsible for delays in the imple- mentation of OF testing in regulated drug testing programs. Stability of D9-tetrahydrocannabinol (THC) fortified and authentic specimens was examined after routine collection, transport and laboratory test- ing. Acceptable recovery and stability were observed when THC-for- tified OF (1.5 and 4.5 ng/mL) was applied to Oral-Eze devices. Neat OF samples collected with Oral-Eze, processed per the package in- sert, and fortified with THC (3 and 6 ng/mL) were stable ( +20%) at room temperature (21 - 258C), refrigerated (2 - 88C) and frozen (225 to 2158C) conditions up to 1 month, while samples collected with Intercept devices showed decreases at refrigerated and room temperatures. After long-term refrigerated or frozen storage, maxi- mum reductions in THC concentrations were 42% for Oral-Eze and 69% for Intercept. After ≥1 year frozen storage, 80.7% of laboratory specimens positive for THC (3 ng/mL cut-off ) by GC - MS were recon- firmed positive (within 25%), with an average THC decrease of 4.2%. Specimens (n 5 47) processed with Oral-Eze (diluted) and tested via enzyme immunoassay were concordant with LC - MS-MS results and showed 100% sensitivity and 95% specificity. Paired specimens col- lected with Oral-Eze and Intercept exhibited 98% overall agreement between the immunoassay test systems. Collectively, these data demonstrate consistent and reproducible recovery and stability of THC in OF after collection, transport and laboratory testing using the Oral-Eze OF Collection System. [ABSTRACT FROM AUTHOR]