Université de Fribourg

THCCOOH concentrations in whole blood: Are they useful in discriminating occasional from heavy smokers?

Fabritius, Marie ; Favrat, Bernard ; Chtioui, Haithem ; Battistella, Giovanni ; Annoni, Jean-Marie ; Appenzeller, Monique ; Dao, Kim ; Fornari, Eleonora ; Lauer, Estelle ; Mall, Jean-Frédéric ; Maeder, Philippe ; Mangin, Patrice ; Staub, Christian ; Giroud, Christian

In: Drug Testing and Analysis, 2013, vol. 6, no. 1-2, p. 155–163

Some forensic and clinical circumstances require knowledge of the frequency of drug use. Care of the patient, administrative, and legal consequences will be different if the subject is a regular or an occasional cannabis smoker. To this end, 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) has been proposed as a criterion to help to distinguish between these two groups of users. However, to...

Université de Fribourg

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

Fabritius, Marie ; Chtioui, Haithem ; Battistella, Giovanni ; Annoni, Jean Marie ; Dao, Kim ; Favrat, Bernard ; Fornari, Eleonora ; Lauer, Estelle ; Maeder, Philippe ; Giroud, Christian

In: Analytical and Bioanalytical Chemistry, 2013, vol. 405, no. 30, p. 9791–9803

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....