Discussion
We performed a randomized, placebo-controlled, double-blind trial to investigate the effect of preventive treatment with acetazolamide on visuomotor performance in middle-aged individuals 40 years of age or older acutely exposed to high altitude. In participants taking placebo, performance during 60° adaptation and immediate recall was impaired at 3,100 m compared to 760 m, whilst post-sleep recall was not significantly affected. Treatment with acetazolamide improved performance during post-sleep recall, but not immediate recall and 60° adaptation. Additionally, worsening of correct test execution at altitude during adaptation and post-sleep recall was prevented by acetazolamide. These novel findings may have important implications for professionals and tourists travelling to high altitude.