European Journal of Clinical Pharmacology

, Volume 56, Issue 8, pp 537–544

Effect of three caffeine doses on plasma catecholamines and alertness during prolonged wakefulness

  • G.H. Kamimori
  • D.M. Penetar
  • D.B. Headley
  • D.R. Thorne
  • R. Otterstetter
  • G. Belenky
Clinical Trials

DOI: 10.1007/s002280000186

Cite this article as:
Kamimori, G., Penetar, D., Headley, D. et al. Eur J Clin Pharmacol (2000) 56: 537. doi:10.1007/s002280000186

Abstract.

Objective: Determine the relationship between caffeine, catecholamines, and alertness during prolonged wakefulness. Methods: Following 49 h of prolonged wakefulness, each of 50 healthy males (18–32 years) orally ingested either a placebo or one of three doses of caffeine, 2.1 (low), 4.3 (medium), or 8.6 mg kg–1 body weight (high), in a randomized double-blind design. Wakefulness continued for an additional 12 h during which venous blood samples were collected for catecholamine and caffeine analysis [determined using high-performance liquid chromatography (HPLC)]. A sleep latency test, the Stanford sleepiness scale, and a choice reaction time test were administered periodically during the post-dosing period and served as measures of alertness (physiological, subjective, and behavioral, respectively). Results: Caffeine had no significant effect on noradrenaline, but adrenaline was significantly increased between 1 h and 4 h post-dosing in the high dose group compared with a placebo group. Following caffeine administration, responses to sleep latency, sleepiness scores, and reaction time scores showed dose-related changes that were exhibited by significant correlation coefficients. Conclusion: The results indicate that high doses of caffeine have a significant and beneficial effect on alertness during prolonged wakefulness.

Caffeine Catecholamines Sleep latency 

Copyright information

© Springer-Verlag 2000

Authors and Affiliations

  • G.H. Kamimori
    • 1
  • D.M. Penetar
    • 2
  • D.B. Headley
    • 1
  • D.R. Thorne
    • 1
  • R. Otterstetter
    • 1
  • G. Belenky
    • 1
  1. 1.Department of Neurobiology and Behavior, Division of Neuropsychiatry, Walter Reed Army Institute of ResearchWashingtonUSA
  2. 2.U.S. Army Research Institute of Environmental MedicineNatickUSA