Computer-analysed EEG and psychometric assessment of two new non-benzodiazepine tranquillizers in healthy volunteers

The effects on CEEG, psychomotor performance and attention of diazepam 10 mg, RU 43028 100 mg, RU 32698 100 mg and placebo administered orally have been investigated in 12 healthy subjects in a double‐blind controlled study. The effects of the compounds were evaluated by objective tests (CEEG, measurement of body sway, critical flicker fusion, visual reaction time, tapping test, arithmetical calculation) and subjective measurements (visual analogue scales and side‐effects questionnaire). Measurements were taken before treatment and after 30 min, 2 h, 3.5 h and 6.5 h. Placebo and RU 43028 did not affect any of the tests used. Diazepam induced an increase in beta rhythms and a decrease in theta and alpha rhythms on CEEG. These expected patterns were correlated with plasma concentrations. It also induced sedative side‐effects characterized by an increase of body sway and reaction time and a decrease of CFF and arithmetical calculation. RU 32698 displayed on atypical profile on CEEG with a reduction of alpha and theta rhythms without changes in beta and delta rhythms. It did not have any psychometric incapacitating effect.