Effect analysis of three anti-motion sickness drugs on vestibular-auditory cognitive and autonomic responses

Abstract

Objective Space motion sickness is one of the inevitable problems that space medicine should face to. At present the administering anti-motion sickness drugs is the most widely used prevention and therapy path. But nearly all drugs have side effects on cognitive function and those effects would be changed by vestibular stimuli. Effects of three anti-motion sickness drugs (difenidol hydrochloride, dimenhydrinate and promethazine hydrochloride) on vestibular-cognitive interaction and vestibular autonomic response were explored. Methods The experiment was done along with 4 × 4Latin Square design and the double blind medication. Eight male volunteers were exposed to vestibular stimuli after administering drugs for 30-40 minutes. They were asked to complete auditory cognitive task during vestibular stimuli under the monitoring of electroencephalogram and electrocardiogram.The P3 component of event-related potentials and heart rate variability parameters were analyzed upon different drugs. Results The order of vestibular autonomic responses inhibition was promethazine hydrochloride, dimenhydrinate, difenidol hydrochloride, placebo, and the order of vestibular-cognitive processing inhibition was promethazine hydrochloride, dimenhydrinate, placebo, difenidol hydrochloride. Conclusions It is suggested that difenidol hydrochloride would be the first choice in case of same vestibular stimuli and less severe motion sickness symptoms. Key words: Vestibule; Auditory perception; Event-related potentials, P300; Heart rate; Dimenhydrinate; Promethazine; Difenidol hydrochloride; Drug evaluation