Study of effects of clobazam and lorazepam on memory and cognitive functions in healthy subjects

Abstract

AbstractThis was a double‐blind, placebo‐controlled crossover study in 15 healthy female volunteers. It consisted of five sessions, separated by 1 week wash‐out between sessions. The purpose of the trial was to study the potential amnesic and sedative activity of clobazam and lorazepam, and the potential antagonism between these effects under the joint influence of a high noise level and intense intermittent light stimulation (ILS), aimed at increasing the level of alertness. The study drugs were administered as a single daily oral dose. The amnesic and sedative effects were evaluated by objective measurements (digit span, Buschke selective reminding test, critical flicker fusion, reaction time, tapping, mental arithmetic test) and subjective measurements (visual analogue scale and adverse effect questionnaire) before each administration, then 1 h, 2 h, 2·5 h, 3 h, 4 h and 7 h post‐dosing. An analysis of variance according to a balanced Latin square design was performed. Clobazam, at a dosage of 10 mg, was devoided of sedative and amnesic effects; at a dosage of 30 mg it induced only moderate memory disturbances. In contrast, lorazepam, administered at doses of 1 and 3 mg, produced marked and dose‐dependent disturbances of memory, alertness and cognitive functions. The use of visual and sound stimuli, designed to increase the level of alertness, did not counteract the sedative effects induced by lorazepam.