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Many Americans are unaware that their prescription meds make them less-safe drivers

The findings suggest that simply increasing warnings may not be enough to get people to change their behavior. Even when drivers are told — and remember — the risks, they may not believe them.

Benzodiazepines have been found to impair driving more than alcohol.
MinnPost file photo by Judy Keen

One in five Americans taking prescription drugs are unaware that their meds make it more difficult for them to drive safely, according to a study published in the November issue of the Journal of Studies on Alcohol and Drugs.

The findings are troubling, for other research has reported a significant relationship between the use of certain prescription drugs and traffic crashes. Europeans researchers have found, for example, that drivers taking benzodiazepines (which are used to treat a host of psychological and physical conditions, including anxiety, insomnia, restless leg syndrome, seizures, and the sedation of patients before dental procedures) are up to seven times more likely to be involved in a car crash causing serious injury or death than drivers not taking the drugs.

In fact, benzodiazepines have been found to impair driving more than alcohol. 

But benzodiazepines are not the only prescription drugs that can affect driving. Other medications of particular concern include antidepressants (which can cause drowsiness); stimulates (which can increase attention but also aggressiveness and risk-taking); sedatives such as barbiturates, muscle relaxants and sleep aids (which, like benzodiazepines, can cause drowsiness and impede the ability to think and move quickly); and opioids/narcotics (which can also cause drowsiness and impair thinking and motor skills).

Study details

For the current study, researchers at West Virginia University’s Injury Control Research Center analyzed data collected anonymously from 7,405 drivers who participated in the 2013-2014 National Roadside Survey. This government survey is done periodically to assess substance use among U.S. drivers.  In the 2013-2014 survey, substance use was expanded to include prescription drugs.

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Almost 20 percent of the 7,405 drivers reported taking at least one potentially impairing prescription drug within the previous two days, and 78 percent of them said the drug was prescribed for their personal use.

But many of those drivers said they were unaware that the medication could affect their competency behind the wheel, even though they should have received such a warning from their doctor and/or pharmacist  — or from the drug’s label itself.

The percentages of people who reported not receiving a warning varied by the type of medication: 14 percent for sedatives, 15 percent for narcotics, 37 percent for antidepressants and 42 percent for stimulants.

“Drugs most commonly perceived as affecting safe driving [by the study’s participants] were sleep aids followed by morphine/codeine, other amphetamines and muscle relaxants,” the researchers write.

The drugs least likely to be viewed as impairing driving (even though they do) were stimulants used to treat attention deficit hyperactivity disorder (ADHD).

The study also found that certain demographic groups had higher or lower odds of being knowledgeable about the risks of driving while under the influence of a drug that had been prescribed to them 

“Overall, the odds of reporting warnings for prescription drugs of any kind were significantly higher for Black/African American drivers compared with non-Hispanic White drivers and for Midwest drivers compared with those in the West,” the researchers write.

Reasons unknown

Why are so many American drivers unaware that the prescription drugs they are taking may be putting their life and the lives of others in danger on the road?

Unfortunately, this study was not designed to answer that question. The findings suggest, however, that simply increasing warnings may not be enough to get people to change their behavior. Other measures similar to those used to deter people from driving while under the influence of alcohol — roadside testing, higher insurance premiums and license suspensions — may be needed.

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“All of these medications should carry warning labels, but they appear not to be recognized and/or remembered by many drivers,” the University of West Virginia researchers explain. “Similarly, although providers may be viewed as having an ethical and professional responsibility to fully inform patients of the potential for driving impairment and related legal risks, many drivers in our study either did not receive warnings or did not recall them.” 

Yet even when drivers are told — and remember — the risks, they may not believe them.

“Among drivers who reported receiving warnings, a substantial proportion did not think it likely that taking the drug as prescribed could affect their ability to drive safely, cause a crash, or lead to criminal justice involvement,” the study’s authors point out. “This is not surprising, as these drugs have the potential to impair driving, but do not do so in all cases.”

“Nevertheless, drivers should be aware that these drugs have the potential to impair driving and lead to legal consequences,” they add. “At least one study demonstrated that patients using drugs affecting the central nervous system poorly predicted their level of driving impairment, suggesting that drivers may not be able to accurately assess the risks of driving while using these medications.”

In other words, you may think the drugs are having no effect on your driving, but they are.

For more information: The study can be read in full at the Journal of Studies on Alcohol and Drugs’ website. You’ll find more information about specific medication and driving risks at the U.S. Food and Drug Administration’s website