Comparison of cannabinoid concentrations in oral fluid and whole blood between occasional and regular cannabis smokers prior to and after smoking a cannabis joint

Abstract

A cross-over controlled administration study of smoked cannabis was carried out on occasional and heavy smokers. The participants smoked a joint (11 % Δ9-tetrahydrocannabinol (THC)) or a matching placebo on two different occasions. Whole blood (WB) and oral fluid (OF) samples were collected before and up to 3.5 h after smoking the joints. Pharmacokinetic analyses were obtained from these data. Questionnaires assessing the subjective effects were administered to the subjects during each session before and after the smoking time period. THC, 11-hydroxy-THC (11-OH-THC) and 11-nor-9-carboxy-THC (THCCOOH) were analyzed in the blood by gas chromatography or liquid chromatography (LC)-tandem mass spectrometry (MS/MS). The determination of THC, THCCOOH, cannabinol (CBN), and Δ9-tetrahydrocannabinolic acid A (THC-A) was carried out on OF only using LC-MS/MS. In line with the widely accepted assumption that cannabis smoking results in a strong contamination of the oral cavity, we found that THC, and also THC-A, shows a sharp, high concentration peak just after smoking, with a rapid decrease in these levels within 3 h. No obvious differences were found between both groups concerning THC median maximum concentrations measured either in blood or in OF; these levels were equal to 1,338 and 1,041 μg/L in OF and to 82 and 94 μg/L in WB for occasional and heavy smokers, respectively. The initial WB THCCOOH concentration was much higher in regular smokers than in occasional users. Compared with the occasional smokers, the sensation of confusion felt by the regular smokers was much less while the feeling of intoxication remained almost unchanged.

Long-Term Effects of Cannabis on Brain Structure

“…The determination of cannabinoid time profiles revealed that the THCCOOH median level was significantly higher in regular smokers compared with occasional users (21 μg/l vs 0 μg/l just before smoking the joint). An equal difference was found for the participants enrolled in the same study and selected by Fabritius et al , (2013a) for the pharmacokinetic determinations.…”

“…Subjects were recruited through public advertisements at universities. The mean consumption of cannabis for the 3 months preceding inclusion in the study was set to a minimum of one joint per month and a maximum of less than one joint per week for the occasional smokers, and to a minimum of 10 joints per month for regular ones (Fabritius et al , 2013a). All volunteers had no history of neurological or psychiatric disorders.…”

“…Participants also filled out a questionnaire about their usual drug use habits. Cannabinoid time profiles in whole blood were determined with the analytical procedures described by Fabritius et al (2013a). Presence of other illicit drugs (cocaine, opiates, and amphetamines) and a positive breath alcohol test were also considered as exclusion criteria.…”

Comparison of Cannabinoid Concentrations in Plasma, Oral Fluid and Urine in Occasional Cannabis Smokers After Smoking Cannabis Cigarette

“…The total quantity of THC used during smoking session was approximately 20 mg., As a comparison, Mariani et al [14] reported that an amount of 0.66 g is used in making joints in the USA (generally uncut with [10]. Concerning kinetic profiles and pharmacokinetic parameters, it is known that the bioavailability of THC after cannabis cigarette smoking is variable and influenced by an individual technique and experience [15].…”

“…The reported few clinical studies, were mainly short termed, with limited information on the metabolites [10][11][12]. Information on the simultaneous concentration and time-course of THC and its metabolites in oral fluid, plasma and urine are, therefore, needed.…”