A comparison of the effects of atenolol and metoprolol on attention.

Additional side-effects of two beta-blockers, atenolol (hydrophilic) and metoprolol (lipophilic), were measured in 18 normal male volunteers in a randomized double-blind placebo-controlled crossover study. A saccadic eye movement reaction time (RT) task, a manual RT version of the Stroop Colour-Word Task, the Span of Apprehension Task, and the Continuous Performance Task were presented on a graphics display screen. Standard cognitive effects were replicated on all measures. Atenolol was noticeably, but not significantly, superior to metoprolol in visual alerting and in angular breadth of visual information processing, both with saccadic RT.