Common Medications Can Impair Driving

From the WebMD Archives

Jan. 24, 2000 (Washington) -- Reading the labels on medications may seem like a cure for insomnia, but it may alert you to possible risks like falling asleep behind the wheel of your car.

Earlier this month, the National Transportation Safety Board concluded that driver drowsiness from an over-the-counter cold/allergy product contributed to a June 1998 Greyhound bus crash that killed seven. The safety board recommended that the FDA establish "clear, consistent" warning labels for all medications.

Nonprescription drugmakers are already in the process of complying with new FDA regulations announced last March that require more prominent placement and larger type for the warnings.

The FDA notes that although it approves safety labels for prescription drugs, it is up to physicians and pharmacists to communicate these risks to the patient. "We're concerned about this," agency spokesperson Crystal Wyland tells WebMD. "We're out there encouraging pharmacists to communicate with consumers and health care professionals, and for consumers to read the label."

Corinne Russell, spokesperson for the Consumer Healthcare Products Association, recommends: "Read the label before you take anything to make sure you are aware of any possible side effects, such as drowsiness. It is on the label."

Reading may not, however, bring understanding. Stephanie Faul, a spokesperson for the AAA Foundation for Traffic Safety, tells WebMD, "A lot of people don't make the connection that [the warning] 'Do not use while operating heavy machinery' means a car."

Federal authorities estimate that about 100,000 crashes each year are caused by drivers nodding off behind the wheel. Of those wrecks, about 1,500 are fatal.

According to a study released last month by the University of North Carolina Highway Safety Research Center, drivers taking medications that may cause drowsiness were vulnerable to crashes. Lead investigator Jane Stutts, PhD, tells WebMD, "Those in sleep or fatigue crashes were 4-5 times more likely to be taking medications."

In its recommendations this month, the safety board asked the Transportation Department to develop a list of medications that may be used safely by professional motor vehicle operators. The board also called for comprehensive toxicology testing after some fatal crashes to better establish the role of prescription and over-the-counter medications in accidents.

What are the riskiest medications? According to Stan Reents, PharmD, editor in chief of ClinicalPharmacology, over-the-counter antihistamines often cause drowsiness. These and other nonprescription drugs may also contain alcohol. As for prescription drugs, he singles out Valium (diazepam), as well as antipsychotics and some antidepressants, barbiturates, and codeine-containing products.

While health care professionals play a role in communicating risks to patients, Reents notes that retail pharmacists are increasingly pressed for time. "There's always been an ethical duty on the pharmacist to warn," he says, but he points out there is sometimes a gap between "ideally what should they do and practically what can they do."

Meanwhile, drug makers are touting new pharmaceuticals that minimize the side effects of sleepiness. One example is Wyeth-Ayerst's Sonata (zaleplon), an insomnia drug that brings relatively little next-day drowsiness. According to Mark Bennett, a spokesman for the product, "Older drugs with [next-day] residual effects cause motor impairment -- and subsequently accidents -- for many people."