Featured Research

from universities, journals, and other organizations

First-Generation Antihistamine Has More Impact Than Alcohol On Driving Performance

Date:
March 9, 2000
Source:
University Of Iowa
Summary:
A medication commonly found in over-the-counter cold and allergy remedies may cause more driving impairment than being legally drunk. University of Iowa researchers made the finding by studying the driving performance of people who had hay fever and were given diphenhydramine (Benadryl), fexofenadine (Allegra), alcohol and a placebo.

IOWA CITY, Iowa -- A medication commonly found in over-the-counter cold and allergy remedies may cause more driving impairment than being legally drunk. University of Iowa researchers made the finding by studying the driving performance of people who had hay fever and were given diphenhydramine (Benadryl), fexofenadine (Allegra), alcohol and a placebo.

Related Articles


The subjects' performance, tested in the Iowa Driving Simulator, was poorest after taking diphenhydramine, even poorer than when they were legally drunk. In comparison, performance after taking fexofenadine was comparable to performance after taking the placebo, an inactive substance. The UI investigators were the first to compare the two medications and alcohol in individuals driving in a high-fidelity driving simulator. The findings will appear in the March 7 issue of the Annals of Internal Medicine.

"First-generation antihistamines, such as diphenhydramine, are known to affect driving performance. However, we were surprised to find that this antihistamine has more impact on driving performance than alcohol does," said John M. Weiler, M.D., UI professor of internal medicine and the study's lead author. "In contrast, we found that fexofenadine, or Allegra, a second-generation antihistamine, did not impair driving performance."

Weiler added that participants could not predict their driving impairment based on how drowsy they felt.

"Drowsiness was only weakly associated with minimum following distance, steering instability and crossing into the left lane," he said. "These results suggest that people should carefully read warning labels on all medications. Even if you do not feel drowsy after taking an antihistamine or alcohol, you may be impaired."

The investigators studied 40 licensed drivers, ages 25 to 44, who had hay fever -- allergies to ragweed pollen -- and who had previously used antihistamines to treat the condition. Allergic rhinitis affects more than 39 million people in the United States.

"It is not commonly recognized that more than half of the states have laws prohibiting driving under the influence of sedating medications," Weiler said.

The researchers tested the participants' ability to follow a lead car that changed its speed randomly. Alcohol-treated subjects performed this task well, but drove closer to the car and had less steering control. Weiler noted that previous studies have shown that drunk drivers may perform one task well but at the expense of other crucial driving tasks. When taking fexofenadine or the placebo, participants matched the speed of the lead car and followed it at a safer distance than when they received alcohol.

Subjects had greater trouble steering and crossed the centerline more frequently after alcohol and diphenhydramine use. However, they did not experience such impairment after taking fexofenadine.

Weiler said this second-generation antihistamine does not appear to cause impairment in driving performance perhaps because, unlike diphenhydramine, it does not pass the blood-brain barrier, which otherwise may cause drowsiness and impairment.

"Overall, our observations suggest that the second-generation antihistamine is less impairing than alcohol or the first-generation antihistamine," Weiler said.

He added that the Iowa Driving Simulator (IDS) allowed the investigators to examine performance in a manner not possible with lower fidelity driving simulators or with on-the-road driving.

The National Advanced Driving Simulator, the world's most advanced driving simulator, will be housed at the UI and replace the IDS in July.

The UI study was supported in part by grants from the National Institutes of Health and from Hoechst Marion Roussel, Inc., Kansas City, Mo. The company is now called Aventis Pharmaceuticals, Inc., and manufactures Allegra.

(Editors: To receive a copy of the journal article mentioned in the release, contact the American College of Physicians -American Society of Internal Medicine at (215) 351-2656.)

University of Iowa Health Care describes the partnership between the UI College of Medicine and the UI Hospitals and Clinics and the patient care, medical education and research programs and services they provide.


Story Source:

The above story is based on materials provided by University Of Iowa. Note: Materials may be edited for content and length.


Cite This Page:

University Of Iowa. "First-Generation Antihistamine Has More Impact Than Alcohol On Driving Performance." ScienceDaily. ScienceDaily, 9 March 2000. <www.sciencedaily.com/releases/2000/03/000309075245.htm>.
University Of Iowa. (2000, March 9). First-Generation Antihistamine Has More Impact Than Alcohol On Driving Performance. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2000/03/000309075245.htm
University Of Iowa. "First-Generation Antihistamine Has More Impact Than Alcohol On Driving Performance." ScienceDaily. www.sciencedaily.com/releases/2000/03/000309075245.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins