(±)-CP 55,940 was one of the first bicyclic mimetics of Δ9-THC found to have superior analgesic properties. The racemic mixture of CP 55,940 is 20- to 100-fold more effective than Δ9-THC in altering the reactions to thermal, mechanical and chemical pain in mice (e.g., 50% maximum possible effect (MPE50) observed in the tail clamp assay at 0.46 and 29.1 mg/kg for (±)-CP 55,940 and Δ9-THC, respectively). CP 55,940 has also been used to identify and characterize the central cannabinoid (CB1) receptor in rat brain membranes. The capacity to displace CP 55,940 from CB1 receptor in rat brain preparations has frequently been used in the characterization of novel cannabimimetics.
