Skip the auto shop - Our mechanics make house calls

Is It Safe to Drive While Taking Antihistamines?


Of course you know better than to drive while impaired by alcohol, and you would never drive while using illegal drugs. But what about those over-the-counter remedies that bring relief from common ailments, like the flu, a cold, or allergies? One of the most common categories of drug given over the counter are called antihistamines, and they can definitely work to impair your driving skills. To understand why this happens, let’s talk a bit about what antihistamines are, and how they work.

When you have an attack of hay fever, it is because your body is producing histamines. Histamines are found in all humans, and most other animals. They serve a valuable function, aiding in digestion and helping to transmit messages from one nerve to another. When you come into contact with something you are allergic to, or when you develop a cold, your body goes into overdrive and produces too much of what is normally a helpful substance. Then, you need antihistamines to suppress the histamine production. The trouble is that antihistamines, in addition to easing the symptoms of your cold or allergy, can also have undesirable side effects.

Here are some things to consider before driving, if you have been taking anti-histamines:

  • Antihistamines can make you drowsy. In fact, if you looked at the ingredient list on the Nytol, Sominex or another brand of sleep aid you buy when you just can’t get to sleep, and compared it with your allergy medication, you would see that the ingredients are identical. The reason is simple – antihistamines make you sleepy. The corollary to that is that when you are sleepy, you are not alert, and probably shouldn’t be behind the wheel of a car.

  • The effect of antihistamines can be aggravated by alcohol. Of course we hope that you are not in the habit of drinking and driving, but you might not realize that even a single glass of wine, coupled with an antihistamine, can make you seriously impaired. In fact, it can make you up to three times as drowsy.

  • OTC antihistamines are not adjusted for weight. The dosage in an over-the-counter antihistamine is geared toward the average person. If you are small, you will be more affected by an antihistamine than a larger person.

You could, of course, buy a so-called “non-drowsy” antihistamine, but many people report that, with this type of medication, they don't become drowsy but they do feel a sense of “nothing above the neck.” This isn't good if you are about to get behind the wheel. Our final word on the topic is, if you are using antihistamines, you should avoid driving.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How Long Does a Fuel Filler Neck Last?
Getting gas from the pump to your gas tank is the only way to keep a car going. The fuel filler neck is a metal tube that is welded to the...
How to Buy Fuel Treatments
Adding a fuel additive to your gas tank when you fill up is one way to clean vital engine parts of deposits, improve the performance of your engine,...

Related questions

Q: How do you reinstall a head restraint?

If you’ve had to remove your head restraints to fold your second row seats down or to haul cargo, you’ll eventually need to reinstall them to use the seats to carry passengers. Here’s how to reinstall your active head restraints:...

Q: Leaf broke while driving

Hello! Thank you for writing in about this problem. This is a well-documented problem with this generation of Tacoma. There is an open recall for this specific problem. In order to properly resolve this issue, contact your local Toyota dealer,...

Q: How do I use Uconnect voice command to override a prompt?

When you are using Uconnect, you will often be given a list of different prompts to choose from. You can wait until the list is complete to select a prompt, or you can override the prompts so that you don’t...