Cannabis is first converted to an active metabolite, 11-hydroxy-delta-9-tetrahydrocannabinol (11-OH-THC), and then to its inactive form, 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH) by the cytochrome family of enzymes [73, 74]. We are only aware of one study that found that CYP2C9*3 carriers were more likely to have higher concentrations of THC and, correspondingly, lower concentrations of THC-COOH and show greater sedation upon oral THC administration [75].
