Though many people think of impaired driving as the result of alcohol or illegal drug use, over the counter (OTC) medications can have side effects that dangerously affect your ability to safely drive a car in much the same way.
Side effects such as drowsiness and disorientation are the most dangerous for drivers, and many common OTC medications warn of these side effects. You should always read all facts and warnings on the label of any medication you are taking and look for warnings if you know you will be driving.
According to Ali Mohamadi, M.D., a medical officer at the Food and Drug Administration (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’ve 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.
Here are some common OTC’s that can impair you when driving:
- Antihistamines: These are medicines 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 the nausea, vomiting, and dizziness associated with motion sickness, can cause drowsiness and drastically impair your ability to drive.
If you need to take one of these medications, it is safest if you can completely avoid driving. Simply planning ahead can be the easiest way to prevent the danger of driving while impaired from an OTC medication. Have a friend or family member take you where you need to go while you are on these medicines, or consider using a ride-share service or public transportation.
If you cannot avoid driving, do not take these medications for several hours before you know you have to leave home. If your driving is impaired, you could risk your safety, and the safety of your passengers and others.
 US Food and Drug Administration “Caution: Some Over-the-Counter Medicines May Affect Your Driving” October 7, 2014