Many older drivers are taking multiple medications that may increase the risk of car crashes, a new U.S. study released today suggests. Half of older drivers interviewed for the AAA Foundation for Traffic Safety study were taking seven or more medications, and one quarter was taking 11 or more, researchers found.

And nearly one in five were taking medications the American Geriatrics Society has called potentially inappropriate medications or PIMs. According to the society, these medications should be avoided by seniors because they have minimal benefit, pose excess harm, or both.

Most of these PIMs, which include benzodiazepines and some antihistamines, have been shown to cause impairments, such as blurred vision, confusion, fatigue or incoordination. Other research has shown that these medications can raise the risk of a crash by up to 30%, the AAA Foundation researchers note in their report.

Currently, 42 million adults age 65 and older are driving on U.S. roads, and the number is expected to increase substantially over the next decade, according to AAA. "The good news is that a lot of things can be done about this," said Jake Nelson, AAA director of Traffic Safety Research and Advocacy.

Healthcare providers and pharmacists 

"By working shoulder to shoulder with healthcare providers and pharmacists, we can mitigate the risks by letting older drivers take the medications they need while allowing them to drive safely. The bad news is that patients are not having the necessary conversations with their doctors and pharmacists," said Nelson.

An earlier study found that "when it came to families discussing driving behaviors with older members, 83% reported they had never had a conversation," said Tara Kelley-Baker, data and information group leader at the AAA Foundation for Traffic Safety in Washington, DC.

Another earlier study found that fewer than 2 in 10 older patients said they had received a warning from healthcare providers about how their prescriptions might impact their driving.

For the new report, researchers from the AAA Foundation and study sites in five states analyzed data from 2,949 seniors participating in the AAA LongROAD study. When the seniors enrolled, they were aged 65 to 79 and were asked to put all their medications, including vitamin and food supplements and over-the-counter drugs, in a bag and bring them to be reviewed.

Participants brought a total of 24,690 medications to the review sessions. Overall, while 3% of participants took no drugs and 10% took two or fewer, 10% received 16 or more, and 1% took 26 or more. 73% of participants took at least one drug for heart disease, and 70% received a drug that affects the central nervous system.

Of particular concern to the researchers were the medications that were potentially inappropriate for older adults, which would include drugs that impair physical or mental function, such as narcotic pain medications, anti-anxiety cations like benzodiazepines and sleep aids. Along with the potential adverse effects on driving ability, these medications are also associated with adverse effects, such as hip fractures, depression and incontinence.