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Published on: February 11, 2019
Effect of a single dose of dextromethorphan on psychomotor performance and working memory capacity
Hayder M Al-Kuraishy1, Ali I Al-Gareeb, Ammar Waham Ashor
1Department of Pharmacology, College of Medicine, Al-Mustansiriya University, Baghdad, Iraq.
Background:
Previous studies show that the prolonged use of dextromethorphan produces cognitive deterioration in humans.
Aim:
The aim of this study was to investigate the effect of a single dose of dextroemthrophan on psychomotor performance and working memory capacity.
Materials And Methods:
This is a randomized, double-blind, controlled, and prospective study. Thirty-six (17 women, 19 men) medical students enrolled in the study; half of them (7 women, 11 men) were given placebo, while the other half (10 women, 8 men) received dextromethorphan. The choice reaction time, critical flicker fusion threshold, and N-back working memory task were measured before and after 2 h of taking the drugs.
Results:
Dextromethorphan showed a significant deterioration in the 3-back working memory task (P<0.05). No significant changes were seen as regards the choice reaction time components (total, recognition, motor) and critical flicker fusion threshold (P>0.05). On the other hand, placebo showed no significant changes as regards the choice reaction time, critical flicker fusion threshold, and N-back working memory task (P>0.05).
Conclusion:
A single dose of dextromethorphan has no effect on attention and arousal but may significantly impair the working memory capacity.
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