Oral Fluid Cannabinoids in Chronic, Daily Cannabis Smokers during Sustained, Monitored Abstinence

Abstract

BACKGROUND Oral fluid (OF) is an accepted alternative biological matrix for drug treatment, workplace, and DUID (driving under the influence of drugs) investigations, but establishing the cannabinoid OF detection window and concentration cutoff criteria are important. METHODS Cannabinoid concentrations were quantified in OF from chronic, daily cannabis smokers during monitored abstinence. Δ9-tetrahydrocannabinol (THC)3, cannabidiol (CBD), cannabinol (CBN), and 11-nor-9-carboxy-THC (THCCOOH) were determined in daily OF samples collected with the Quantisal™ device. GC-MS limits of quantification (LOQ) were 0.5 μg/L for THC and CBD, 1 μg/L for CBN, and 7.5 ng/L for THCCOOH. RESULTS After providing written informed consent for this institutional review board–approved study, 28 participants resided from 4 to 33 days on the secure research unit and provided 577 OF specimens. At the LOQ, THC was generally quantifiable for 48 h, whereas CBD and CBN were detected only at admission. Median THCCOOH detection time was 13 days (CI 6.4–19.6 days). Mean THC detection rates decreased from 89.3% at admission to 17.9% after 48 h, whereas THCCOOH gradually decreased from 89.3% to 64.3% within 4 days. Criteria of THC ≥2 μg/L and THCCOOH ≥20 ng/L reduced detection to <48 h in chronic cannabis smokers. An OF THCCOOH/THC ratio ≤4 ng/μg or presence of CBD or CBN may indicate more recent smoking. CONCLUSIONS THC, THCCOOH, CBD, and CBN quantification in confirmatory OF cannabinoid testing is recommended. Inclusion of multiple cannabinoid cutoffs accounted for residual cannabinoid excretion in OF from chronic, daily cannabis smokers and could reduce the potential for positive test results from passive cannabis smoke exposure and lead to greatly improved test interpretation.

Extended Detection of Amphetamine and Methamphetamine in Oral Fluid

“…From the creatinine-correlated concentrations in corresponding urine samples, new ingestions were not suspected. This phenomenon also was observed in urine samples 4,6 and was reported also for THC 26,27 and benzodiazepines. 28 Detection times in different matrices are highly dependent on cutoff concentrations; lowering the cutoff inevitably leads to longer detection times.…”

Developing Public Health Regulations for Marijuana: Lessons From Alcohol and Tobacco

“…The main psychoactive constituent in marijuana is THC, and although its acute psychoactive effects often last only a few hours, it remains detectable in blood for several hours and, for some chronic users, up to 7 days after use. 87 Furthermore, metabolites typically included in specific tests of urine are detectable for even longer. 85,87 Therefore, detection of use can occur well outside the window of impairment.…”

“…87 Furthermore, metabolites typically included in specific tests of urine are detectable for even longer. 85,87 Therefore, detection of use can occur well outside the window of impairment.…”

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

“…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. Detecting multiple cannabinoids and using oral fluid/plasma ratios are promising ways to indicate recent use, however more research is required before these can be used to determine more accurate windows of detection [103,104].…”