The benzodiazepine antagonist, Ro 15-1788, prevents the effects of flurazepam on the high pressure neurological syndrome.

The benzodiazepine antagonist, Ro 15-1788, was used to investigate the anticonvulsant effect of flurazepam on the high pressure neurological syndrome (HPNS). Flurazepam raised the threshold pressures for the onset of tremor and of clonic convulsions caused by high pressure helium. Administration of the benzodiazepine antagonist Ro 15-1788 completely prevented the changes in threshold pressures produced by flurazepam. Alone, Ro 15-1788 did not affect the onset pressures. The concentration of Ro 15-1788 which blocked the actions of flurazepam on the pressure signs was the same as that required to prevent its effects on convulsions due to infusion of bicuculline. It is concluded that the effect of flurazepam on thresholds for the high pressure neurological syndrome is due to action at benzodiazepine receptors and not to a nonspecific effect.