title: Evaluation of the effects of anti-motion sickness drugs on subjective sleepiness and cognitive performance of healthy males.
abstract: This study aimed to investigate the clinical and cognitive side effects of baclofen (10 mg), meclizine (25 mg), dimenhydrinate (40 mg) plus cinnarizine (25 mg) and promethazine (25 mg) plus d-amphetamine (10 mg). The study had a double-blind, placebo controlled, repeated measures design and was conducted on healthy male volunteers. The psychomotor vigilance test, the Sternberg working memory task, the implicit memory test and the automated Operation Span (Ospan) task were performed. The Stanford, the Karolinska and the Epworth Sleepiness scale determined the degree of sleepiness. The Profile of Mood States (POMS) evaluated mood states and adverse effects were reported on a 22-item questionnaire. Letter recalls and time for solving mathematical problems, recorded during the Ospan task, were impaired by baclofen and dimenhydrinate-cinnarizine respectively, suggesting an influence of these drugs on the working memory. Significant side effects for baclofen were: sleepiness, tiredness, blurred vision, concentration problems and dizziness whereas for dimenhydrinate-cinnarizine only sleepiness and blurred vision were reported. Meclizine decreased the accuracy on the Sternberg working memory task and thus seemed to affect short-term memory. A reported side effect was increased sleepiness. Promethazine plus d-amphetamine did not affect any of the tested cognitive functions. However, many side effects such as sleepiness, dry mouth, dizziness, vertigo, confusion, insomnia and tremors were reported. The results show that meclizine and dimenhydrinate combined with cinnarizine were the two drugs with the most acceptable combination of side effects.
authors.affiliation: Antwerp University Research Center for Equilibrium and Aerospace, University of Antwerp, Antwerp, Belgium.
authors.forename: A P
authors.initials: AP
authors.lastname: Weerts
authors.affiliation: Research Unit VIPER, Royal Military Academy, Brussels, Belgium Research Unit Biological Psychology, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Pattyn
authors.affiliation: Antwerp University Research Center for Equilibrium and Aerospace, University of Antwerp, Antwerp, Belgium.
authors.forename: P H
authors.initials: PH
authors.lastname: Van de Heyning
authors.affiliation: Antwerp University Research Center for Equilibrium and Aerospace, University of Antwerp, Antwerp, Belgium Floris.Wuyts@uantwerpen.be.
authors.forename: F L
authors.initials: FL
authors.lastname: Wuyts
mesh_terms: D000328:Adult; D000932:Antiemetics / Q000009:adverse effects / Q000494:pharmacology*; D001418:Baclofen / Q000494:pharmacology; D002936:Cinnarizine / Q000494:pharmacology; D003071:Cognition / Q000187:drug effects*; D003072:Cognition Disorders / Q000139:chemically induced / Q000175:diagnosis / Q000523:psychology; D004111:Dimenhydrinate / Q000494:pharmacology; D004311:Double-Blind Method; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects; D008569:Memory Disorders / Q000139:chemically induced / Q000175:diagnosis / Q000523:psychology; D008875:Middle Aged; D009041:Motion Sickness / Q000517:prevention & control* / Q000523:psychology; D009483:Neuropsychological Tests; D011398:Promethazine / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects; D012890:Sleep / Q000187:drug effects*; D012893:Sleep Wake Disorders / Q000139:chemically induced / Q000175:diagnosis / Q000523:psychology; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D000932:Antiemetics; D002936:Cinnarizine; D011398:Promethazine; D001418:Baclofen; D004111:Dimenhydrinate
keywords: Short-term memory; implicit memory; pharmacological effects; psychomotor performance; working memory