Cannabis Edibles: Blood and Oral Fluid Cannabinoid Pharmacokinetics and Evaluation of Oral Fluid Screening Devices for Predicting Δ9-Tetrahydrocannabinol in Blood and Oral Fluid following Cannabis Brownie Administration

BACKGROUND: Roadside oral fluid (OF) Δ 9 -tetrahydrocannabinol (THC) detection indicates recent cannabis intake. OF and blood THC pharmacokinetic data are limited and there are no on-site OF screening performance evaluations after controlled edible cannabis. CONTENT: We reviewed OF and blood cannabinoid pharmacokinetics and performance evaluations of the Draeger DrugTest ® 5000 (DT5000) and Alere™ DDS ® 2 (DDS2) on-site OF screening devices. We also present data from a controlled oral cannabis administration session. SUMMARY: OF THC maximum concentrations (C max ) were similar in frequent as compared to occasional smokers, while blood THC C max were higher in frequent [mean (range) 17.7 (8.0–36.1) μg/L] smokers compared to occasional [8.2 (3.2–14.3) μg/L] smokers. Minor cannabinoids Δ 9 -tetrahydrocannabivarin and cannabigerol were never detected in blood, and not in OF by 5 or 8 h, respectively, with 0.3 μg/L cutoffs. Recommended performance (analytical sensitivity, specificity, and efficiency) criteria for screening devices of ≥80% are difficult to meet when maximizing true positive (TP) results with confirmation cutoffs below the screening cutoff. TPs were greatest with OF confirmation cutoffs of THC ≥1 and ≥2 μg/L, but analytical sensitivities were 80% with an OF THC ≥5 μg/L cutoff. Performance criteria also were >80% with a blood THC ≥5 μg/L confirmation cutoff; however, positive OF screening results might not confirm due to the time required to collect blood after a crash or police stop. OF confirmation is recommended for roadside OF screening. ClinicalTrials.gov identification number: NCT02177513