Dose‐effect study of levomepromazine on psychomotor and memory tasks in healthy volunteers

Abstract

AbstractThe effects of single doses of levomepromazine (3, 6 and 12 mg) on psychomotor skills and memory tasks, as well as haemodynamic and pupil diameter parameters, were assessed in 12 normal volunteers. Each subject was given three of the four treatments, at a weekly interval in a double‐blind crossover randomized balanced incomplete‐block design. The three doses and a placebo were monitored using a battery of tests including critical flicker fusion (CFF), choice reaction time (CRT), subjective ratings and memory tasks before, 3 and 6 hours after drug intake. Supine standing blood pressure and pupil diameter were recorded at the same times.Compared to placebo, levomepromazine impaired both subjective and objective vigilance measures in a dose‐related manner, with 3 mg affecting only some subjective ratings, while 12 mg impaired most objective and subjective vigilance evaluations with a moderate effect on memory tasks (i.e. anterograde amnesia). Pupil diameter was reduced by the evaluations with a moderate effect on memory tasks (i.e. anterograde amnesia). Pupil diameter was reduced by the three doses. In conclusion, levomepromazine at low doses induced a sedative effect the intensity and duration of which are compatible with its use as an hypnotic.