Restricted sedation and absence of cognitive impairments after administration of intranasal scopolamine.
BACKGROUND
Space motion sickness in astronauts during spaceflight causes significant discomfort, which might impede their functionality. Pharmacological treatment has been mainly restricted to promethazine. Transdermal and oral scopolamine have also been used in space; however, their use was reduced due to unpredictable effectiveness and side effects. Recently, intranasal scopolamine administration has gained much interest, since this route ensures fast and reliable absorption with a decreased incidence of undesirable side effects. The aim of this study was to evaluate the effect of intranasal scopolamine on cognitive performance and to determine its side effects.


METHODS
This double-blind, placebo controlled, repeated measures study evaluated vigilant attention, short-term memory, implicit memory and working memory. Side effects were reported on a 22-item questionnaire and sleepiness was assessed by the Karolinska, Stanford and Epworth Sleepiness Scales.


RESULTS
Scopolamine had no effect on cognitive function. Only the Karolinska score was significantly increased for scopolamine compared to placebo. Participants reported a dry mouth and dizziness after receiving scopolamine.


CONCLUSIONS
Results show that intranasal scopolamine did not impair cognitive performance. Intranasal scopolamine might be a good alternative to promethazine for the alleviation of space motion sickness, since the agent has minimal sedative effects and does not hamper cognitive performance.
Antwerp University Research Centre for Equilibrium and Aerospace (AUREA), Antwerp University Hospital and University of Antwerp, Antwerp, Belgium.
Aurélie P
AP
Weerts
Research Unit VIPER, Department LIFE, Royal Military Academy, Brussels, Belgium Research Unit Biological Psychology, Department of Experimental and Applied Psychology, Vrije Universiteit Brussel, Brussels, Belgium.
Nathalie
N
Pattyn
Biomedical Operations and Research Branch, NASA - Johnson Space Center, Houston, TX, USA.
Lakshmi
L
Putcha
School of Pharmacy, Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD, USA.
Stephen W
SW
Hoag
Antwerp University Research Centre for Equilibrium and Aerospace (AUREA), Antwerp University Hospital and University of Antwerp, Antwerp, Belgium.
Angelique
A
Van Ombergen
Antwerp University Research Centre for Equilibrium and Aerospace (AUREA), Antwerp University Hospital and University of Antwerp, Antwerp, Belgium.
Emma
E
Hallgren
Antwerp University Research Centre for Equilibrium and Aerospace (AUREA), Antwerp University Hospital and University of Antwerp, Antwerp, Belgium.
Paul H
PH
Van de Heyning
Antwerp University Research Centre for Equilibrium and Aerospace (AUREA), Antwerp University Hospital and University of Antwerp, Antwerp, Belgium Floris.Wuyts@uantwerpen.be.
Floris L
FL
Wuyts
D000281:Administration, Intranasal / Q000379:methods; D000328:Adult; D001288:Attention / Q000187:drug effects; D003071:Cognition / Q000187:drug effects*; D003072:Cognition Disorders / Q000503:physiopathology*; D004311:Double-Blind Method; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D018727:Muscarinic Antagonists / Q000008:administration & dosage; D012601:Scopolamine / Q000008:administration & dosage*; D055815:Young Adult
D006993:Hypnotics and Sedatives; D018727:Muscarinic Antagonists; D012601:Scopolamine
Space motion sickness; implicit memory; intranasal scopolamine; short-term memory; working memory