Nomifensine, clobazam and HOE 8476: effects on aspects of psychomotor performance and cognitive ability

The effects of a combination of nomifensine and clobazam (HOE 8476) were compared, on a variety of psychometric measures, with those of its separate monosubstances in a placebo controlled double-blind study with twelve normal volunteers. Assessments comprised a range of psychomotor performance tests, measures of cognitive processing ability and visual analogue rating scales - previously shown to be sensitive to the effects of psychotropic drugs. Subjects acted as their own control and were tested in the morning and afternoon following subchronic pre-dosing with each of the four treatments. When compared with placebo, nomifensine showed no significant change on any of the performance measures. HOE 8476 produced no significant changes in performance but significantly reduced self-rated anxiety. Clobazam significantly improved subjective ratings of the ease of getting to sleep and impaired choice reaction time and concept identification performance in the morning. No significant changes in the test measures were found in the afternoon following any treatment. The findings were in broad agreement with those of previous studies and demonstrated that clobazam and nomifensine, both alone and in combination, tended not to impair performance on a wide range of psychological test assessments.