Phencyclidine-like behavioral effects of 2-methyl-3,3-diphenyl-3-propanolamine (2-MDP)

2-Methyl-3,3-diphenyl-3-propanolamine (2-MDP) produced effects in animals similar to those produced by the dissociative anesthetics such as phencyclidine (PCP). Specifically, it shared the discriminative stimulus properties of PCP in rats trained to discriminate PCP (1 mg/kg) from saline; at higher doses, it disrupted brightness discrimination and stimulated locomotor activities in rats trained to avoid shocks in an automated Y-maze; and it produced surgical anesthesia when injected IV to rhesus monkeys. These pharmacological activities were observed only with the levo-isomer of 2-MDP. The dextro-isomer was either inactive or produced opposite effects, depending on the tests. Among several related diphenylpropylamines, 2-MDP represents the optimal structure for potency of PCP-like effects since changes in the amino, 2-methyl and 3-hydroxy groups reduced the potencies of the PCP-like discriminative properties.