睡眠劑와 認知機能 ㅡ정상 성인에서 취침시 일회 투여된 치료적 용량의 Triazolam과 Zopiclone이 인지기능에 미치는 영향 一

Hypnotics and Cognitive Function — Effect of Single Therapeutic Doses of Triazolam and Zopiclone at Bedtime on Cognitive Function in Normal Adult Subjects —

This study, one of the serial studies, is concerned with effects of hypontics on cognitive function, given in a typical therapeutic dosage at bedtime. Triazolam 0.25mg, zopicione 0.75mg or placebo were administrated orally to normal male adult subjects at bedtime. This study took place in three consecutive seesions separated by one week interval in accordance with a repeated measures double-blind design with the order of the drugs counterbalanced over the subjects. Cognitive performance was assessed at 30 minutes, four hours and eight hours after the administration of the drugs using a battery of cognitive tests (continuous arithmetic, digit span, symbol copy, digit symbol substitution test and free recall). In all the tests except digit span, the performance was significantly affected by the time of assessment but not by the drug condition. The performance generally decreased 4 hours after treatment and then improved 8 hours after treatment approximately to the performance level at the 30 minutes after treatment. Specifically this effect of the testing times was more sensitive in both zopicione and triazolam conditions than in the placebo condition. In free recall test a significant interaction between drug condition and testing time was also found. Follow-up analysis of this interaction showed that zopicione condition significantly impaired performance compared to both triazolam and the placebo conditions, at four hours after treatment however there was no difference amongest the drug conditions at 30 minutes and eight hours after treatment. These results suggest that extent to which the cognitive performance is impaired by single therapeutic doses of triazolam and zopicione administered at bedtime seems to be ascribed to the testing times rather than the hypnotics. But this interpretation should be considered in terms of circadian rhythms of sleepiness and cognition, sleepiness secondary to the hypnotics, pharmacokinetics and pharmacodynamics of the drugs, and sensitivity of the cognitive tests.