Anyone who operates a vehicle of any type—car, bus, train, plane, or boat—needs to know there are over-the-counter medicines that can make you drowsy and can affect your ability to drive and operate machinery safely.
Over-the-counter medicines are also known as OTC or nonprescription medicines. All these terms mean the same thing: medicines that you can buy without a prescription from a healthcare professional. Each OTC medicine has a Drug Facts label to guide you in your choices and to help keep you safe. OTC medicines are serious medicines and their risks can increase if you don’t choose them carefully and use them exactly as directed on the label.
According to Ali Mohamadi, M.D., a medical officer at FDA, “You can feel the effects some OTC medicines can have on your driving for a short time after you take them, or their effects can last for several hours. In some cases, a medicine can cause significant ‘hangover-like’ effects and affect your driving even the next day.” If you have not had enough sleep, taking medicine with a side effect that causes drowsiness can add to the sleepiness and fatigue you may already feel. Being drowsy behind the wheel is dangerous; it can impair your driving skills.
Choosing and Using Safely
You should read all the sections of the Drug Facts label before you use an OTC medicine. But, when you know you have to drive, it’s particularly important to take these simple steps:
First, read the “active ingredients” section and compare it to all the other medicines you are using. Make sure you are not taking more than one medicine with the same active ingredient. Then make sure the “purpose” and “uses” sections of the label match or fit the condition you are trying to treat.
Next, carefully read the entire “Warnings” section. Check whether the medicine should not be used with any condition you have, or whether you should ask a health care professional whether you can use it. See if there’s a warning that says when you shouldn’t use the medicine at all, or when you should stop using it.
The “When using this product” section will tell you how the medicine might make you feel, and will include warnings about drowsiness or impaired driving.
Look for such statements as “you may get drowsy,” “marked drowsiness will occur,” “Be careful when driving a motor vehicle or operating machinery” or “Do not drive a motor vehicle or operate machinery when using this product.”
Other information you might see in the label is how the medicine reacts when taken with other products like alcohol, sedatives or tranquilizers, and other effects the OTC medicine could have on you. When you see any of these statements and you’re going to drive or operate machinery, you may want to consider choosing another medicine for your problem this time. Look for an OTC medicine that treats your condition or problem but has an active ingredient or combination of active ingredients that don’t cause drowsiness or affect your ability to drive or operate machinery.
Talk to your healthcare professional if you need help finding another medicine to treat your condition or problem. Then, check the section on “directions” and follow them carefully.
Here are some of the most common OTC medicines that can cause drowsiness or impaired driving:
- Antihistamines: These are medicines that are used to treat things like runny nose, sneezing, itching of the nose or throat, and itchy or watery eyes. Some antihistamines are marketed to relieve cough due to the common cold. Some are marketed to relieve occasional sleeplessness. Antihistamines also can be added to other active ingredients that relieve cough, reduce nasal congestion, or reduce pain and fever. Some antihistamines, such as diphenhydramine, the active ingredient in Benadryl, can make you feel drowsy, unfocused and slow to react.
- Antidiarrheals: Some antidiarrheals, medicines that treat or control symptoms of diarrhea, can cause drowsiness and affect your driving. One of these is loperamide, the active ingredient in Imodium.
- Anti-emetics: Anti-emetics, medicines that treat nausea, vomiting and dizziness associated with motion sickness, can cause drowsiness and impair driving as well.
“If you don’t read all your medicine labels and choose and use them carefully,” says Dr. Mohamadi, “you can risk your safety. If your driving is impaired, you could risk your safety, and the safety of your passengers and others.”
Please visit, Over-the-Counter Medicines and Driving, for the audio and slide presentation for more about driving and OTC medicines and with practice looking at Drug Facts labels.