Effects of fexofenadine, diphenhydramine, and alcohol on driving performance:​ a randomized, placebo-controlled trial in the Iowa driving simulator

Weiler, John M.; Bloomfield, John R.; Woodworth, George G.; Grant, Angela R.; Layton, Teresa A.; Brown, Timothy L.; McKenzie, David R.; Baker, Thomas W.; Watson, Ginger S.

Affiliations

¹University of Iowa Hospitals and Clinics, T307, 200 Hawkins Drive, Iowa City, IA 52242

²Department of Statistics, University of Iowa,241 Schaeffer Hall, Iowa City, IA 52242.

³1660 Fulmer Street, Ann Arbor, MI 48103

⁴4133 SC, University of Iowa, Iowa City, IA 52242

⁵Quintiles, Inc., Box 9708, Kansas City, MO64134-0708

⁶Aventis Pharmaceuticals, Inc., Box 9627, Kansas City,MO 64134-0627

⁷ational Advanced Driving Simulator, 2401 Oakdale Boulevard, University of Iowa, Iowa City, IA 52242

Abstract and keywords

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.

Keywords: Rhinitis, allergic; Fexofenadine; Diphenhydramine; Antihistamines; Automobile driving

Links

PubMed: 10691585

WoS: 000085563000003

Cited By (1)

Year	Entry
2013	Brown T, Milavetz G, Murry DJ. Alcohol, drugs and driving: implications for evaluating driver impairment. In: 57th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). September 22-25, 2013; Quebec City, QC.23-32.