Dronabinol also known as (−)-trans-delta9-tetrahydrocannabinol is an active ingredient of cannabis. The drug was approved by FDA for the treatment of anorexia in patients with AIDS and chemotherapy-induced nausea and vomiting. Dronabinol exerts its action by activating CB1 and CB2 recepors which makes it a CNS active medicine.

11-NOR-9-CARBOXY-DELTA9-TETRAHYDROCANNABINOL (THC-COOH) is the main the non-psychoactive metabolite of Delta9-Tetrahydrocannabinol. Being most abundant in bodily fluids, it has become an established marker of cannabis consumption in forensic, clinical and environmental analyses. Among the cannabinoids tested as potential inhibitors of the drug efflux transporter P-glycoprotein (Pgp), which is responsible for the multidrug-resistance of a tumour and normal cells, THC-COOH behaved as a substrate and was the most active in stimulating Pgp-dependent ATPase. It displayed analgesic and anti-inflammatory properties apparently by inhibiting cyclooxygenase and 5-lipoxygenase activities. THC-COOH was not an anxiolytic or anxiogenic drug but abolished the anxiogenic behavioral effect of Delta9-Tetrahydrocannabinol.