title: 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.
authors.affiliation: UTCF (Forensic Toxicology and Chemistry Unit), CURML (University Center of Legal Medicine), Rue du Bugnon 21, 1011, Lausanne, Switzerland.
authors.forename: Marie
authors.initials: M
authors.lastname: Fabritius
authors.forename: Haithem
authors.initials: H
authors.lastname: Chtioui
authors.forename: Giovanni
authors.initials: G
authors.lastname: Battistella
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Annoni
authors.forename: Kim
authors.initials: K
authors.lastname: Dao
authors.forename: Bernard
authors.initials: B
authors.lastname: Favrat
authors.forename: Eleonora
authors.initials: E
authors.lastname: Fornari
authors.forename: Estelle
authors.initials: E
authors.lastname: Lauer
authors.forename: Philippe
authors.initials: P
authors.lastname: Maeder
authors.forename: Christian
authors.initials: C
authors.lastname: Giroud
mesh_terms: D000293:Adolescent; D000328:Adult; D002853:Chromatography, Liquid / Q000379:methods*; D018592:Cross-Over Studies; D013759:Dronabinol / Q000097:blood* / Q000378:metabolism / Q000493:pharmacokinetics; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D008385:Marijuana Smoking; D012463:Saliva / Q000737:chemistry*; D015813:Substance Abuse Detection / Q000379:methods*; D053719:Tandem Mass Spectrometry; D013997:Time Factors; D014018:Tissue Distribution; D055815:Young Adult
chemical_list: D013759:Dronabinol