title: No effects of anti-motion sickness drugs on vestibular evoked myogenic potentials outcome parameters.
abstract: OBJECTIVE
  To investigate the effects of meclizine (50 mg), baclofen (10 mg), cinnarizine (20 mg) + dimenhydrinate (40 mg), and promethazine (25 mg) + dextro-amphetamine (5 mg) on the parameters of the vestibular evoked myogenic potential (VEMP) test.
  
  
  METHODS
  Double-blind placebo-controlled prospective randomized trial.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Twenty-four (first block: baclofen versus placebo) and 20 healthy male subjects (second block: meclizine, cinnarizine + dimenhydrinate and promethazine + dextro-amphetamine versus placebo).
  
  
  METHODS
  VEMP test.
  
  
  METHODS
  Threshold, p13 and n23 latencies, p13-n23 latency difference, p13-n23 peak-to-peak amplitude, mean rectified voltage of the sternocleidomastoid muscle contraction and the corrected amplitude.
  
  
  RESULTS
  There were no clinically significant pharmacologic effects on the VEMP outcome parameters. However, there was a statistically significant left-right asymmetry after intake of the combination promethazine + d-amphetamine for the parameters p13 and latency difference.
  
  
  CONCLUSIONS
  The absence of clinically significant effects can be explained by the predominant presence of the target receptors for the applied drugs in the medial vestibular nucleus, which receives the lowest grade of saccular projections. It also can be hypothesized that the VEMP methodology and techniques in general do not allow determining pharmacologic effects in a healthy group of subjects because of a too small discriminative power. The left-right asymmetry can be explained by a depressive action of the drugs on the central compensation mechanisms. Because there were no significant differences between the VEMP parameters obtained after intake of the placebos of both blocks, we concluded that there were no training effects.
authors.affiliation: Antwerp University Research Center for Equilibrium and Aerospace, University of Antwerp, Antwerp, Belgium. robby.vanspauwen@gmail.com
authors.forename: Robby
authors.initials: R
authors.lastname: Vanspauwen
authors.forename: Aurélie
authors.initials: A
authors.lastname: Weerts
authors.forename: Marilyn
authors.initials: M
authors.lastname: Hendrickx
authors.forename: Kristof I
authors.initials: KI
authors.lastname: Buytaert
authors.forename: Cathérine
authors.initials: C
authors.lastname: Blaivie
authors.forename: Philippe G
authors.initials: PG
authors.lastname: Jorens
authors.forename: Paul H
authors.initials: PH
authors.lastname: Van de Heyning
authors.forename: Floris L
authors.initials: FL
authors.lastname: Wuyts
mesh_terms: D000328:Adult; D000932:Antiemetics / Q000494:pharmacology*; D002936:Cinnarizine / Q000494:pharmacology*; D004111:Dimenhydrinate / Q000494:pharmacology*; D004311:Double-Blind Method; D006634:Histamine H1 Antagonists / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008468:Meclizine / Q000494:pharmacology*; D011398:Promethazine / Q000494:pharmacology*; D011446:Prospective Studies; D058585:Vestibular Evoked Myogenic Potentials / Q000187:drug effects*
chemical_list: D000932:Antiemetics; D006634:Histamine H1 Antagonists; D002936:Cinnarizine; D008468:Meclizine; D011398:Promethazine; D004111:Dimenhydrinate