title: Dimenhydrinate effect on cerebral oxygen status and salivary chromogranin-A during cognitive tasks.
abstract: To investigate the effects of dimenhydrinate on cerebral oxygen status (COS; cerebral oxygenated hemoglobin concentration changes) and salivary chromogranin-A (CgA) during a cognitive test battery, a double-blind, placebo-controlled, randomized, crossover protocol was used to examine the effect of 50 mg of dimenhydrinate or placebo in 12 subjects. This test battery includes tests of both reaction time and fundamental cognitive ability and was used in the assessment of pilots. Poor cognitive performance was observed in the subjects taking dimenhydrinate. We used two-channel near-infrared spectroscopy to investigate the effects of dimenhydrinate on the COS. With the one exception of shifting attention task in the left forehead, no significant difference was found between dimenhydrinate and placebo during the tasks of the test battery. Under placebo treatment, on the other hand, CgA levels were significantly elevated during cognitive testing when compared with baseline. However, CgA levels were not significantly elevated above baseline following dimenhydrinate. The present study is one of the first to demonstrate that the first-generation antihistamine drugs altered the responses of salivary CgA during cognitive tasks. The changes in salivary CgA secretion, as a result of dimenhydrinate administration, may serve as a sensitive biomarker of a psychological status such as a drug-induced sedation during the performance of a cognitive test battery. Further studies, however, are required to examine the usefulness of this sensitive biomarker in investigation of psychological agents during cognitive tasks.
authors.affiliation: 2nd Division, Aeromedical Laboratory, Japan Air Self-Defense Force, 1-2-10 Sakae-cho, Tachikawa-shi, Tokyo 190-8585, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Kanamaru
authors.forename: Azusa
authors.initials: A
authors.lastname: Kikukawa
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: Masahiko
authors.initials: M
authors.lastname: Hirafuji
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002540:Cerebral Cortex / Q000098:blood supply / Q000187:drug effects*; D053379:Chromogranin A / Q000378:metabolism*; D003071:Cognition / Q000187:drug effects*; D018592:Cross-Over Studies; D004111:Dimenhydrinate / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006634:Histamine H1 Antagonists / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012463:Saliva / Q000187:drug effects; D019265:Spectroscopy, Near-Infrared / Q000379:methods; D013997:Time Factors
chemical_list: D053379:Chromogranin A; D006454:Hemoglobins; D006634:Histamine H1 Antagonists; D004111:Dimenhydrinate