The effect of antimotion sickness drugs on habituation to motion.
The effect of antimotion sickness drugs on habituation was studied. Subjects were rotated once a day for 5 d to the malaise III end-point after receiving placebo, 1 mg scopolamine, 10 mg d-amphetamine, or the combination of 0.6 mg scopolamine with 5 mg of d-amphetamine. The placebo scores had a Spearman coefficient of correlation of 0.88 with the initial untreated tests. This demonstrated a high reliability for the M-III end-point and that little habituation resulted from the test design. The combination of 0.6 scopolamine with 5 mg amphetamine produced the fastest rate of habituation closely followed by the dose of 1 mg scopolamine. 10 mg of d-amphetamine also produced an increase in habituation over placebo scores. When the medications were discontinued on day 5 a rebound in sensitivity to vestibular stimulation occurred with scopolamine and scopolamine with d-amphetamine. The increased habituation appears to be due to the greater exposure to vestibular stimulation permitted by the medications.
D000293:Adolescent; D000328:Adult; D003913:Dextroamphetamine / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006185:Habituation, Psychophysiologic / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D009041:Motion Sickness / Q000503:physiopathology / Q000517:prevention & control*; D010919:Placebos; D011897:Random Allocation; D012399:Rotation; D012601:Scopolamine / Q000008:administration & dosage / Q000627:therapeutic use*; D013997:Time Factors
D010919:Placebos; D012601:Scopolamine; D003913:Dextroamphetamine