Caffeine counteracts impairments in task-oriented psychomotor performance induced by chlorpheniramine: a double-blind placebo-controlled crossover study.
This study aimed to evaluate the effects of chlorpheniramine on psychomotor performance and the counteracting effects of caffeine on those sedative antihistamine actions. Sixteen healthy young men participated in this study. Using a double-blind placebo-controlled crossover design, each subject was administered one of the following conditions in a random order with a one-week interval: 'placebo-placebo', '4 mg of chlorpheniramine-placebo', 'placebo-200 mg of caffeine' or '4 mg of chlorpheniramine-200 mg of caffeine'. Before and after the treatments, psychomotor functions were assessed using a battery of tests. Additionally, subjective responses were assessed using a visual analogue scale (VAS). Psychomotor performance changed over time in different ways according to the combination of study medications. In the 'chlorpheniramine-placebo' condition, reaction times of the compensatory tracking task were significantly impaired compared with the other three conditions. In addition, the number of omission errors of the continuous performance test were significantly greater compared with the 'placebo-caffeine' condition. However, the response pattern of the 'chlorpheniramine-caffeine' condition was not significantly different from that of the 'placebo-placebo' condition. Changes of VAS for sleepiness were significantly greater in the 'chlorpheniramine-placebo' condition compared with the other three conditions. In conclusion, chlorpheniramine significantly increases subjective sleepiness and objectively impairs psychomotor performance. However, caffeine counteracts these sedative effects and psychomotor impairments.
Department of Psychiatry, Chonnam National University Medical School, Gwangju, Republic of Korea.
Sung-Wan
SW
Kim
Kyung-Yeol
KY
Bae
Hee-Young
HY
Shin
Jae-Min
JM
Kim
Il-Seon
IS
Shin
Jong-Keun
JK
Kim
Gaeun
G
Kang
Jin-Sang
JS
Yoon
D000328:Adult; D002110:Caffeine / Q000494:pharmacology*; D002744:Chlorpheniramine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004347:Drug Interactions; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D008297:Male; D011596:Psychomotor Disorders / Q000139:chemically induced* / Q000188:drug therapy*; D011597:Psychomotor Performance / Q000187:drug effects*; D013647:Task Performance and Analysis; D055815:Young Adult
D006993:Hypnotics and Sedatives; D002110:Caffeine; D002744:Chlorpheniramine