Search

Background: Sedating antihistamines may impair driving performance as seriously as alcohol. Objective: To compare the effects of fexofenadine, diphenhydramine, alcohol, and placebo on driving performance. Design: Randomized, double-blind, double-dummy, four-treatment, four-period crossover trial. Setting: The Iowa Driving Simulator. Participants: 40 licensed drivers with seasonal allergic rhinitis who were 25 to 44 years of age. Intervention: One dose of fexofenadine (60 mg), diphenhydramine (50 mg), alcohol (approximately 0.1% blood alcohol concentration), or placebo, given at weekly intervals before participants drove for 1 hour in the Iowa Driving Simulator. Measurements: The primary end point was coherence, a continuous measure of participants' ability to match the varying speed of a vehicle that they were following. Secondary end points were drowsiness and other driving measures, including lane keeping and response to a vehicle that unexpectedly blocked the lane ahead. Results: Participants had significantly better coherence after taking alcohol or fexofenadine than after taking diphenhydramine. Lane keeping (steering instability and crossing the center line) was impaired after alcohol and diphenhydramine use compared with fexofenadine use. Mean response time to the blocking vehicle was slowest after alcohol use (2.21 seconds) compared with fexofenadine use (1.95 seconds). Self-reported drowsiness did not predict lack of coherence and was weakly associated with minimum following distance, steering instability, and left-lane excursion. Conclusions: Participants had similar performance when treated with fexofenadine or placebo. After alcohol use, participants performed the primary task well but not the secondary tasks; as a result, overall driving performance was poorer. After participants took diphenhydramine, driving performance was poorest, indicating that diphenhydramine had a greater impact on driving than alcohol did. Drowsiness ratings were not a good predictor of impairment, suggesting that drivers cannot use drowsiness to indicate when they should not drive., Diphenhydramine may affect drivers as seriously as alcohol does. This antihistamine is used in many allergy and hay-fever medications. In a study of 40 people with seasonal hay-fever, one 50-milligram dose of diphenhydramine had a more serious impact on driving than a blood alcohol concentration of 0.1%. Many of the drivers did not even feel drowsy but still performed poorly in the Iowa Driving Simulator. Fexofenadine had no serious impact on driving ability.

A Slew of Standards for Camera Systems Interfacing imaging systems with the variety of camera systems now available presents system integrators with a formidable task. Several factors must be considered […]

Your leader (17 January) singles out bankers as solely culpable for the financial crisis and the ensuing recession. This is neither reasoned nor wholly accurate. Consumers must also shoulder blame [...]

David Blanchflower makes a couple of significant oversights in his economics column (31 May). First, to praise the US Federal Reserve for its 'wait-and-see' approach is fair enough. But the [...]