Pharmacological properties of 6,7-tetramethylene-5-phenyl-1,2-dihydro-3H-thieno[2,3-e](1,4)-diazepin-2-one (QM-6008, thiadipone), a new psychotropic drug.

The pharmacological actions of 6,7-tetramethylene-5-phenyl-1,2,-dihydro-3H-thieno]2,3-e](1,4)-diazepin-2-one (QM-6008, thiadiapone), a new psychotropic drug, have been studied. QM-6008 shares many of the psychosedative effects in rodents of benzodiazepines. The electroencephalographic actions in rats and rabbits of QM-6008 and chlordiazepoxide are also rather similar. This new compounds is endowed with clear conflict attenuating properties in an approach-avoidance schedule and can be considered, in consequence, as a new potentially useful anxiolytic drug. In other operant conditioning procedures in rats--Variable Interval and Discriminated Avoidance--QM-6008 induces an increase in response rate which is not generally shared by chlordiazepoxide. The psychopharmacological data collected in the present work leal to classify this new thienodiazepine derviative within the fram of tranquilizers of the benxodaizapine type. The sedative effects of QM-6008 appear howerer to be less potent and the psychostimulatn effects more markde than those ofchlordiazeposide.