Pipequaline (PK-8165) is an anticonflict & anticonvulsant quinoline derivative. It is an anxiolytic drug that was never marketed. It possesses a novel chemical structure that is not closely related to other drugs of this type. The drug has a similar pharmacological profile to the benzodiazepine family of drugs, but with mainly anxiolytic properties and very little sedative, amnestic or anticonvulsant effects, and so is classified as a nonbenzodiazepine anxiolytic.

Pipequaline is extensively bound to plasma proteins: i.e. human serum albumin (HSA), alpha-1-acid glycoprotein (AAG), lipoproteins and blood cells, mainly erythrocytes[1].

Intravenously administered pipequaline exerts a partial suppression of activations by kainate, glutamate and acetylcholine. Microiontophoretic applications of pipequaline reduces the neuronal activation by kainate[2]. In small intravenous doses, pipequaline potentiated the effect of microiontophoretically-applied flurazepam whereas, in larger doses, it suppressed the effects of microiontophoretically-applied flurazepam and of intravenously administered lorazepam on kainate-induced activation. Pipequaline produces dose-related decreases in motor activity. Pipequaline produces significant dose-related decreases in the number of head-dips made[3].

Rats: Pipequaline is dissolved in water to give injection volumes of 2 mL/kg. Rats are injected with 5, 10, and 50 mg/kg pipequaline. Infrared cells in the walls of the box provided automated measures of locomotor activity and rearing, respectively[3].