Previous studies suggest that sedating antihistamines may impair driving performance as much as alcohol does. The participants in this study had similar simulated driving performance when treated with fexofenadine (a nonsedating drug) or placebo. After alcohol use, participants performed the primary task (matching the varying speed of a vehicle they were following) well but not secondary tasks. After participants received diphenhydramine (a sedating drug), driving performance was poorest, indicating that this drug had a greater effect on driving than alcohol did. (A)
Abstract