Is It *Really* That Bad To Mix Alcohol and Allergy Meds? A Pharmacist Weighs In

I’ve taken a daily Zyrtec pill for as long as I can remember, and I typically head straight to my box of Benadryl after petting a cat or dog (yes, the latter is as sad as it sounds). This is to say, I’m well-acquainted with antihistamines… and the fact that experts warn you not to drink alcohol while on them.

But let’s be real: If a Sex on the Beach is in front of me, I’m going to drink it. The pull of a fun night out is just strong sometimes, even during allergy season.

A pharmacist does have concerns—and for good reason. But there are some smart ways to safely ensure a that night at the bar doesn’t turn into a night at the hospital.

What happens when you combine antihistamines and alcohol?

Putting these two together doesn’t lead to great outcomes. As you might have experienced, antihistamines can have side effects like excessive drowsiness, dizziness, headaches—which you might also experience after drinking.

So, when you combine the two, the risks increase. “Combining alcohol with first-generation antihistamines will worsen these side effects, specifically drowsiness,” says HaVy Ngo-Hamilton, PharmD, a BuzzRx clinical consultant. Extreme drowsiness can increase the chances of an injury or accident, and “lead to serious problems with thinking, judgment, and motor skills,” she warns. Fortunately, some of the newer antihistamines like Zyrtec, Allegra Allergy, and Claritin are less likely to cause drowsiness than first-generation meds like Benadryl and Dramamine.

Another problem: Some types of alcohol, like wine and beer, can basically undo the benefits of an antihistamine. “Drowsiness aside, one interesting fact is that some alcohol types contain histamines,” Dr. Ngo-Hamilton shares, clarifying that histamines cause congestion, runny nose, and sneezing. “Therefore, when taking Zyrtec to relieve seasonal allergies, having a drink at the end of the day can actually worsen allergy symptoms by increasing your exposure to histamines.”

This can happen to anybody, she adds, regardless of how regularly they do or don’t pop an antihistamine. And, Dr. Ngo-Hamilton notes, antihistamines aren’t just your typical Benadryl and Zyrtec—even liquid cough and cold medicines have antihistamines with similar effects.

Can you just take a smaller dose?

Some people try to lower their risk by taking less of their allergy meds on days they plan to have a drink. However, that’s not always a safe workaround. “Theoretically, the higher dose of antihistamine, especially the first generation, the more profound the side effects are,” Dr. Ngo-Hamilton says. “However, people react to medication differently, so a very small dose of antihistamine can sometimes cause dangerous side effects.”

Nasal sprays are a better bet

All of this isn’t fun to learn, I know, but here’s the good news: Nasal sprays can address the same issues as antihistamines without leading to drowsiness and related risks (or at least to the same degree). For springtime allergies, saline nasal sprays, nasal decongestant sprays, nasal antihistamine sprays, and nasal steroid sprays can all provide relief from a runny or itchy nose, sneezing, and itchy or watery eyes, according to Dr. Ngo-Hamilton. And all of them are available over the counter.

“The risk of drowsiness with antihistamine nasal sprays is not zero,” Dr. Ngo-Hamilton says, “but since they act locally, they carry a much lower risk for drowsiness and sleepiness compared to oral antihistamines.” (Phew.)

Perhaps even better, nasal sprays act quickly. “These nasal sprays act within seconds, and their effects last for 12 hours,” Dr. Ngo-Hamilton says. However, she warns against using decongestant sprays for more than three days, as frequent or prolonged use can worsen congestion.

If you’re going to mix, wait it out

Hey, we get it: Some days just call for a drink. If you’re on an oral antihistamine, your best bet is to wait until the medicine or alcohol is out of your system, depending on which one you had first.

This is unfortunately easier said than done. Dr. Ngo-Hamilton explains it may take your body anywhere from hours to days to completely rid itself of an allergy medicine. That exact timeline depends on the type of medication you took, what strength it was, and your personal health history. Alcohol typically takes about six hours, she says, but can take much longer if you live in a smaller body or are older.

However, while there’s no single recommendation, she believes “a generally healthy person can take an allergy medicine 24 hours after the last alcoholic beverage.” But again, she adds, it’s best to talk to your primary care doctor first or a pharmacist.

Already hit by side effects?

So, maybe you’ve already had a drink before you remember that the oral antihistamines you took earlier are still in your system. There’s no need to freak out. Dr. Ngo-Hamilton suggests rest, avoiding driving or other situations that require quick reactions and coordination, and drinking plenty of fluids. If you’re getting a headache or extreme drowsiness, it might be a good idea to check in with your doctor. That said, if you experience seizures, hallucinations, confusion, or difficulty breathing, it’s time to get emergency medical attention.

FWIW: Remember that you may also experience adverse side effects if you combine alcohol and other central nervous system depressants, like pain medicine, sleep aids, anxiety medicine, and seizure drugs, Dr. Ngo-Hamilton says. If you take any of those, it’s best to talk to your doctor or pharmacist before drinking as well.