Which Drugs to Avoid When Taking the Wheel

Reasons for Drivers’ Unawareness

People use drugs for a great variety of reasons, including allergic reactions, cold-related diseases, stresses, depressions, diabetes, cardiovascular diseases (including high blood pressure), headaches and so on. But are they aware of how these drugs can affect their driving abilities?

On the one hand, every driver is supposed to know about the influence of pharmaceutical drugs on human’s mental and physical skills, since this is one of the topics discussed in every driver’s handbook of every state. But virtually, many drivers don’t apply this knowledge to their everyday life situations. Why?

For one thing, there is a problem of people suffering from chronic diseases – they are so accustomed to the need to constantly take certain medications that sooner or later they stop paying attention to possible side effects. Moreover, as many drugs for chronic diseases are prescribed by doctors, drivers tend to shift the responsibility on them, thinking "My doctor should warn me if this medicine can affect my driving abilities." As a result, according to a 2010 study, 47% of drivers who were involved in fatal crashes and tested positive for drugs had taken exactly prescription medicines.

For another thing, there is a problem of over-the-counter drugs like medicines for cold or a headache. These drugs are so common and so highly publicized and, hey, they are sold without any prescriptions – it is no surprise that drivers truly believe that these drugs are completely safe. It seems so obvious that they even don’t bother to read what the instruction says about the influence on the ability to operate vehicles and control mechanisms.

Besides, prescription and over-the-counter drugs are not the only types of products that can have a negative impact on your driving abilities. There are also various food supplements, herbs, homeopathic medicines, which can cause a variety of reactions affecting your ability to drive safely. Since many of them don’t fall into the category of pharmaceutical drugs, they can come with no instructions and warnings about their dangerous impacts.

Moreover, quite often people take more than one drug at a time. Some drug combinations can also lead to various undesirable and unpredictable body responses. The more drugs a person takes, the higher possibility that they will influence his ability to safely drive vehicles. This problem is especially urgent in people with chronic diseases and seniors, who are often forced to take many drugs simultaneously. And elderly people are particularly prone to the development of side effects because of their fragile health and a bunch of various diseases.

Finally, many other things can make a drug affect your body differently, not as usual. Drinking alcohol, certain emotional states, accidental increase in dosage – add some of these factors and your drug, which has never manifested any side effects, will cause drowsiness or blurred vision. And that’s why even drug manufacturers and your doctors cannot predict all possible effects, which drugs can show in drivers. But what are those possible effects?

How Can Drugs Affect Your Driving Ability?

Obviously, the effects of drugs depend on their types and can vary in different people. However, there is a list of the most common reactions, which can be observed in drivers and which can make you a dangerous road user: 

• drowsiness
• blurred vision
• dizziness
• poor reaction
• faint
• nausea
• impaired concentration
• decreased coordination

Some drugs have a sedative effect, slowing your reactions, while other medicines show a stimulating action, forcing you to act more aggressively and thus leading to reckless driving. But which drugs are dangerous for drivers and what effects can you expect from each of them?

According to the latest NHTSA study, the most common medicines observed in US drivers are:

• Antidepressants

These are psychotropic drugs used primarily for depression therapy through affecting the level of neurotransmitters. Drugs based on Fluoxetine, Sertraline, and Tricyclic antidepressants are widely prescribed in the United States for treating not only mental disorders, but also eating and sleep disorders, chronic pain and migraine, dysmenorrhea and other illnesses. At the same time, these drugs can cause drowsiness, have a sedative (calming) action and inhibit psychomotor abilities, thus slowing down and worsening driver’s reaction. They are especially dangerous when taken in combination with alcohol.

• Narcotic analgesics

This class of drugs is also known as painkillers aimed at achieving relief from different types of pain. Drugs like Buprenorphine, Fentanyl, Meperidine, Methadone, Naltrexone, Oxycodone, Propoxyphene, Tramadol act on opioid receptors and produce an effect similar to morphine, also leading to opioid dependence – and thus they are classified as narcotic analgesics. They are mainly used for the treatment of acute pain, moderate or severe, but due to their ability to cause euphoria, they can be misused as recreational drugs. However, after a short period of the euphoric effect, they produce a suppressive action on the central nervous system, worsening your driving performance and also causing nausea, vomiting, and drowsiness.

• Sedatives

Sedatives, including Barbiturates, Benzodiazepines, Zolpidem, are also known as tranquilizers that are used to reduce irritability and excitement through the suppression of central nervous system and brain activity, thus causing a relaxing effect. Besides, they can be prescribed in combination with analgesics to help patients in going through anxiety-provoking procedures like dental treatment or MRI, while barbiturates are widely used in anti-convulsant therapy. Though many sedatives don’t have any hypnotic effect, the above-mentioned drugs cause drowsiness, loss of concentration, dizziness, delayed reaction and slowed reflexes, thus affecting your driving ability badly. 

• Stimulants

Prescription stimulants comprise Amphetamine and Methylphenidate-based drugs used to treat many disorders like obesity, sleep and mood disorders, narcolepsy, chronic pain and attention deficit hyperactivity disorder. They boost mental and physical activity, accelerating brainwork, relieving fatigue and drowsiness, increasing motivation and efficiency, improving mood and motor performance. On the other hand, these drugs build up dependence and lead to nausea, dizziness, headache, abdominal pain, visual impairment and aggressive behavior. As you can see, these effects can hardly correspond to the common notion of safe driving.

• Others

Some other drugs contain certain substances, which can also affect your driving ability.

For example, atropine eye drops are used with the purpose of diagnostics (to dilate the pupils), as well as for therapeutic purposes (to treat acute inflammatory diseases and eye traumas) due to their ability to relax eye muscles. But these eye drops tend to blur vision for a while, and so it is not recommended to drive right after the treatment.

Furthermore, there are popular medicines against diarrhea based on Loperamide opioid (Imodium, among many others). They work fine for people suffering from inflammatory bowel disease, but they also cause drowsiness, nausea, abdominal pain, vomiting, fatigue and dizziness.

And don’t forget about these innocent cold and cough drugs, which contain opioids and antihistaminic agents leading either to hyperexcitability or to sleepiness, not to mention vision changes. This includes popular over-the-counter drugs based on dextromethorphan and codeine, which are frequently abused as recreational drugs, by the way. Also, note that antihistaminic agents can be contained in both cold/cough medicines and antiallergic drugs, having a sedative effect on you. It is true for the first-generation antihistamines, which are non-selective (Ethylenediamines, Ethanolamines, Alkylamines, Piperazines, Tricyclics, and Tetracyclics).

Here you can learn more about some drug effects, including prescription drugs. 

What Can You Do to Avoid Medicated Driving?

When speaking about medicated driving, we need to understand that there are two sides of the same coin.

For one thing, you cannot be safe when driving on medications that can get your vision blurred, your judgment impaired and your reaction delayed.

On the other hand, this is also about your legal responsibility, as medicated driving can fall under DUI penalties. Though driving under the influence is usually associated with alcohol intoxication or something like cocaine or at least marijuana, virtually both prescription and OTC medicines can lead to DUI charges. In a number of states like Minnesota, a zero-tolerance law is established addressing drugged driving. This means that any detectable amount of certain substances, including opiates and even codeine, found in your body can result in your arrest. And 44 states and the District of Columbia adopted specific programs for training police officers to determine drug impairment in motorists on the roads.  

So, what can you do to avoid those risks?

• Talk to a doctor prescribing a medicine for you. Ask about its side effects and in particular its impact on your driving ability. Don’t forget to tell the doctor about other drugs and supplements you take.
• Be especially careful when taking a new medicine for the first time, since you don’t know how it will affect you. Avoid driving after the first intake.
• Read the labels carefully when purchasing OTC drugs and ask a pharmacist for advice. Be especially careful with medicines that belong to the above-mentioned groups. Make sure you read all the information specified on the label including active ingredients, warnings, side effects, contraindications and use with other drugs.
• Strictly follow your doctor’s or manufacturer’s instructions on dosage and other conditions of drug administration.
• Monitor yourself and report to your doctor about all side effects observed. In fact, your doctor can help you to stay sober-minded by changing your dose schedule, diet or medicine in a way that reduces the drug impact on your driving ability.

We also recommend you review your local operator’s handbook to take a close look at the DUI regulations. And it is a great idea to freshen your memory bypassing our driver’s knowledge tests again!