Steer clear: The medications older adults should avoid to stay safe behind the wheel

A new US study has revealed which medications may potentially affect driving ability in older adults and which may have a positive impact on driving performance.

Results of the observational study were published recently on Jama Open Network and interestingly show that some of the most commonly used medications may affect driving performance in seniors.

200 active drivers aged 65 years and over were monitored over a 10 year period. The average age was 72 and participants had to demonstrate sound cognitive health, that they were living in community and driving independently.

35 per cent of participants either failed a practical driving assessment or received a marginal results which reflected sub-par driving ability.

The researchers then analysed which medications were associated with poor driving performance and found that frequently used medications such as paracetamol, non-steroidal anti inflammatory drugs (NSAIDS), anti-depressants, sedatives and hypnotics were associated with poor driving performance.

On the contrary, researchers found that lipid-lowering medications (prescribed to those with high cholesterol or at risk of cardio-vascular disease) were less likely to impair driving performance and antihistamines and anticholinergic medications had no impact on driving performance.

The study authors argue that the reason for these findings is the mechanism of action of psychoactive drugs (drugs that can alter an individual’s perception, mood, consciousness, or behavior) but the role of analgesia (pain reducing drugs) is less clear.

They also hypothesised that lipid-lowering therapy may have benefited drivers by optimising brain health.

The authors wrote, “The negative association between psychoactive drug use and driving performance may be explained by the effect of these drugs on neurotransmitters, such as noradrenaline, serotonin, histamine, acetylcholine, and GABA.”

“Numerous studies have suggested the protective effects of statin on cognitive functioning, which could have a positive impact on driving,” they added.

The researchers were quick to point out that, as an observational study, the findings cannot determine a causal relationship between medication use and driving performance; however, they suggest that doctors should be aware of the results.

“While we cannot determine whether these medications directly caused the risk of decline in driving performance individually or collectively, our results raise concern about the potential negative impact of potentially driver-impairing medications on driving performance,” they wrote.

“Clinicians and pharmacists should be aware that patients who are prescribed these drugs could be at an increased risk of driving impairment. A clear discussion and review of medications in relation to the driving task should be included in the care of older adults.”

Australia has 4.2million active drivers who are aged 65 and over.

Speaking to newsGP, An Rendell, manager of the Assessing Fitness to Drive implementation project at Austroads, referred GPs to the current standards for fitness to drive when considering medication use.

These standards show that most drugs affecting the central nervous system tend not to pose an increased crash risk when drugs are medically prescribed and the patient is using them regularly.

The standards state that benzodiazephines, psychoactive drugs primarily used to treat conditions such as anxiety, insomnia, and certain neurological and psychological disorders, are known to increase the risk of motor vehicle accidents and are found in 4 per cent of fatalities and 16 per cent of hospitalised injured drivers.

Health professionals should consider the following when assessing a patients fitness to drive and advising on their medication:

• the balance between potential impairment due to the drug and the patient’s improvement in health on safe driving ability
• the individual response of the patient – some people are more affected than others
• the type of licence held and the nature of the driving task
• the added risks of combining two or more drugs capable of causing impairment, including alcohol
• the added risks of sleep deprivation on fatigue while driving, which is particularly relevant to commercial vehicle drivers
• the potential impact of changing medications or changing dosage
• the cumulative effects of medications
• the presence of other medical conditions that may combine to adversely affect driving ability
• other factors that may exacerbate risks such as known history of alcohol or drug misuse.