Effects of prochlorperazine on normal vestibular ocular and perceptual responses: a randomised, double-blind, crossover, placebo-controlled study.

BACKGROUND The present study investigated whether prochlorperazine affects vestibulo-ocular reflex (VOR) and vestibulo-perceptual function. METHODS We studied 12 healthy naïve subjects 3 h after a single dose of oral prochlorperazine 5 mg in a randomised, placebo-controlled, double-blind, crossover study in healthy young subjects. Two rotational tests in yaw were used: (1) a threshold task investigating perceptual motion detection and nystagmic thresholds (acceleration steps of 0.5°/s(2)) and (2) suprathreshold responses to velocity steps of 90°/s in which vestibulo-ocular and vestibuloperceptual time constants of decay, as well as VOR gain, were measured. RESULTS Prochlorperazine had no effect upon any measure of nystagmic or perceptual vestibular function compared to placebo. This lack of effects on vestibular-mediated motion perception suggests that the drug is likely to act more as an anti-emetic than as an antivertiginous agent.