On top of that, many of them aren’t aware of the risk.
The study authors used data from the most recent National Roadside Survey (NRS), conducted in 2013-2014 by the National Highway Traffic Safety Administration, to determine what proportion of drivers had been warned that the medication their doctor prescribed could impair their performance. Data were collected from randomly selected drivers at 60 different U.S. locations.
Drivers 16 and older were eligible to participate in the voluntary, anonymous survey about alcohol and drug use. Those who agreed to be surveyed were also asked to provide a breath sample to measure alcohol content and a saliva sample for drug testing.
The 2013-2014 NRS was the second to ask drivers about drug use but the first to ask whether the drug had been prescribed for them and, if so, whether they’d been warned that it could impair their driving. Those who reported taking a prescribed, potentially impairing medication within the previous two days were then asked if they had been warned that it could affect their driving.
These are the categories of potentially impairing prescription drugs covered by the survey and some examples of them:
- Antidepressants (Prozac, Zoloft, Wellbutrin).
- Methadone and buprenorphine (Subutex, Suboxone), opioids that are used in medication-assisted treatment of substance use disorders.
- Morphine or codeine, which are prescription opioids for pain.
- Other prescription opioids (OxyContin and Vicodin), also used to treat pain.
- Barbiturates (phenobarbital).
- Benzodiazepines, which are tranquilizers (Xanax and Valium).
- Muscle relaxants (Soma and Flexeril).
- Sleep aids (Ambien and Lunesta).
- ADHD medications (Ritalin, Aderall and Concerta).
- Other amphetamines (Benzadrine and Dexedrine).
- Prescription diet pills (Tenuate and phentermine).
Except for the last three types of drugs, the medications on this list could impair drivers by sedating them. Experimental studies have shown that certain tranquilizers have a substantially higher risk of impairment than alcohol and that opioids have a risk comparable to that of alcohol, the researchers write.
On the other hand, ADHD medications and other amphetamines as well as prescription diet pills are stimulants, which can influence attention, aggressiveness and risk-taking, the study authors write. You likely won’t fall asleep behind the wheel if you take a stimulant, but you could end up taking unnecessary risks while driving.
A total of 7,405 drivers answered the prescription drug questions on the NRS, and 19.7% of them reported taking a potentially impairing prescription drug within the previous two days. Of those who had, four out of five of them, or 78.2%, to be exact, said the drug had been prescribed for them, so there had been an opportunity for a physician or a pharmacist to talk about the risk of impaired driving.