Effects of prochlorperazine on vestibular ocular and perceptual responses: A randomised, double-blind, cross-over, 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°/s2) 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.