Is It Safe to Take Benadryl, Zyrtec, Claritin, and Allegra Together?
Key takeaways:
Many allergy medications are available over the counter to treat seasonal allergies. Knowing which ones can be taken together is important when it comes to safely treating allergy symptoms.
Allergy medications from different classes can typically be combined. For example, nasal steroids, such as Flonase (fluticasone propionate), and oral decongestants, such as Sudafed (pseudoephedrine), are safe to take together.
Oral antihistamines, such as diphenhydramine (Benadryl) and cetirizine (Zyrtec), shouldn’t be taken together without a healthcare professional’s OK. The combination can raise the risk for serious side effects.
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Once the April showers pass and the May flowers come into full bloom, what often follows is a season filled with watery eyes, runny noses, and congestion. Seasonal allergies, or “hay fever,” affect an estimated 26% of U.S. adults.
Various allergy medications are available for purchase over the counter (OTC) at the pharmacy. Certain medications are safe to mix and take at the same time. But others — especially those that belong to the same medication group — shouldn’t be taken together as their combination can lead to serious problems.
Is it safe to combine allergy medications?
Allergy medications that work differently in the body can be safely taken together. For instance, someone taking an oral antihistamine, such as Zyrtec (cetirizine), can also use a corticosteroid (“steroid”) nasal spray, such as Flonase (fluticasone propionate).
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Nasal sprays, including antihistamines, steroids, and decongestants, are sometimes combined with oral antihistamines to treat allergy symptoms. However, the American Academy of Allergy, Asthma, and Immunology recommends that a steroid or antihistamine nasal spray should first be used by itself to treat allergies since they’re generally more effective than other medication classes.
Examples of allergy medication classes that are generally safe to combine include:
Oral antihistamines and nasal steroids
Nasal steroids and nasal antihistamines
Nasal steroids and antihistamine eye drops
Oral antihistamines and oral decongestants
Nasal steroids and nasal decongestant sprays
Nasal steroids and oral decongestants
Good to know: Ask a healthcare professional before combining an oral antihistamine with an non-oral antihistamine. Examples of non-oral antihistamines include nasal sprays, such as azelastine (Astepro), and eye drops, such as ketotifen (Zaditor). These combinations haven’t been well-studied for safety.
What are the different types of allergy medications?
There are many different allergy medications available. They can be broken down into a few different medication classes.
Allergy medication class | How do they help your allergies? | Which allergy meds are safe to add? | Which allergy meds should you avoid adding? |
|---|---|---|---|
Oral antihistamines (Common examples: Zyrtec, Benadryl, Claritin) | By blocking histamine (a substance that triggers allergy symptoms) | • Nasal steroid • Decongestant (oral, eye drop, or nasal spray) • Leukotriene receptor antagonist | • Another oral antihistamine |
Nasal antihistamines (Common example: Astepro) | By blocking histamine | • Nasal steroid • Decongestant (oral, eye drop, or nasal spray) • Leukotriene receptor antagonist | • Another nasal antihistamine |
Antihistamine eye drops (Common example: Pataday) | By blocking histamine | • Nasal steroid • Decongestant (oral, eye drop, or nasal spray) • Leukotriene receptor antagonist | • Another antihistamine eye drop |
Nasal steroids (Common examples: Flonase, Nasonex, Nasacort) | By lowering your body’s immune response to allergens and reducing swelling in the nose and sinuses | • Nasal antihistamine • Oral antihistamine • Antihistamine eye drop • Decongestant (oral, eye drop, or nasal spray) • Leukotriene receptor antagonist | • Another nasal steroid |
Decongestants (Common examples: Sudafed, Afrin, Visine) | By narrowing blood vessels in and around the nose | • Nasal steroid • Nasal antihistamine • Oral antihistamine • Antihistamine eye drop • Leukotriene receptor antagonist | • Another decongestant (includes all dosage forms) |
Singulair (a leukotriene receptor antagonist) | By blocking certain chemicals in the body that trigger inflammation in the airways | • Nasal steroids • Nasal antihistamines • Oral antihistamines • Antihistamine eye drop • Decongestant (oral, eye drop, or nasal spray) | • N/A; OK to mix with other allergy medications |
Below, you’ll find details about each of these classes of allergy medications.
Antihistamines
Antihistamines are a group of medications that block the effects of histamines in the body. Histamines are chemicals made by your immune system to defend your body from potential threats. Your body releases these chemical signals when you encounter allergens, such as pollen, mold, or pet dander.
The most commonly taken antihistamines are those available as oral pills or liquids. Older antihistamines, also known as first-generation antihistamines, can cause you to feel sleepier than newer antihistamines.
Benadryl (diphenhydramine) is a popular first-generation antihistamine and can cause other common side effects, including:
Dry mouth
Dry eye
Constipation
Blurry vision
Dizziness
Comparing antihistamines? Pharmacists compare Zyrtec, Claritin, and Allegra and highlight their differences.
Your OTC treatment guide: Dive deeper into the best over-the-counter (OTC) options for your allergy symptoms, from decongestants to nasal sprays and more.
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The newer, second- or third-generation antihistamines are less likely than older antihistamines to cause drowsiness. Newer antihistamines include:
These antihistamines also tend to last longer in the body than older antihistamines. Their longer-lasting, but less drowsy qualities are why many healthcare professionals often recommend newer antihistamines for daily allergy relief over older antihistamines.
Antihistamines also come in other forms. Pataday (olopatadine) is an antihistamine eye drop used to treat itching and watery eyes. Antihistamines nasal sprays, such as olopatadine and azelastine, are used to treat nasal symptoms, including runny nose, itchy nose, and stuffiness.
Nasal steroids
Nasal steroids treat allergy symptoms by lowering your body’s immune response to allergens. This leads to less swelling in your nose and sinuses. Examples of popular nasal steroids include:
Decongestants
Allergens can cause the lining of your nose, as well as the blood vessels there, to swell. Decongestants help treat stuffy and congested noses by shrinking swollen blood vessels. These medications can be taken by mouth, as a nasal spray, or as an eye drop to treat allergy symptoms.
Sudafed (pseudoephedrine) is an oral decongestant. Although it can be purchased without a prescription, Sudafed is stored behind the pharmacy counter. Additionally, there are limits to how much can be purchased at a time.
Decongestant nasal sprays, such as Afrin (oxymetazoline), are sprayed in the nose to lower swelling and relieve congestion. Decongestant eye drops like Visine Red Eye Comfort (tetrahydrozoline) can relieve eye redness.
Oral decongestants are also sometimes combined with other allergy medications, notably antihistamines. Popular examples include Allegra-D (fexofenadine / pseudoephedrine) and Zyrtec-D (cetirizine / pseudoephedrine).
Singulair
Singulair (montelukast) is a leukotriene receptor antagonist. It can be a helpful addition for people who have both allergies and asthma (allergic asthma). Singulair works by blocking chemicals called leukotrienes that can create inflammation in your airways. Allergens can trigger your body to produce high levels of leukotrienes, causing your airways to narrow and tighten. This can lead to congestion and stuffiness or worsen existing asthma symptoms.
However, due to the risk of serious behavioral and mood changes, such as suicidal thoughts or actions, the FDA recommends that Singulair only be used for more severe cases of seasonal allergies. And it’s typically combined with other allergy medications if they aren’t working well enough on their own.
Can you take Zyrtec and Benadryl together?
No, you shouldn’t take Zyrtec and Benadryl together. In fact, it’s not typically recommended to combine more than one oral antihistamine. Examples of combinations to avoid include:
Claritin and Benadryl
Claritin and Zyrtec
Allegra and Benadryl
Allegra and Zyrtec
Although you can mix some allergy medications, combining certain medications can raise the risk of serious side effects. Oral antihistamines, such as Zyrtec and Benadryl, shouldn’t be taken together without a healthcare professional’s OK. Combining two or more oral antihistamines can lead to additional side effects and potentially an antihistamine overdose.
Signs and symptoms of an overdose may include the following:
Fast or racing heartbeat
Dry mouth
Agitation
Behavioral changes
Poor balance or coordination
In severe cases, an antihistamine overdose can result in serious complications including cardiac arrest, seizures, and even death.
If someone you know may be experiencing an antihistamine overdose, call 911 immediately or use the Poison Control helpline at 1-800-222-1222.
How long after taking Zyrtec can you take Benadryl?
How long to wait between doses of two oral antihistamines depends on the specific medications. If you’ve taken an antihistamine like Zyrtec, its effects can last for up to 24 hours. So you’d want to wait until it’s been at least 24 hours since taking Zyrtec to take Benadryl (or another antihistamine).
On the flip side, Benadryl doesn’t last as long in the body. One dose typically keeps working for about 4 to 6 hours. So if you’ve taken Benadryl, you should wait at least 6 hours to take Zyrtec or another oral antihistamine.
Does combining allergy medications help or hurt?
In certain situations, your healthcare team may suggest taking both a medication that you take by mouth and a medication that you apply elsewhere, such as a nasal spray or eye drop.
For severe allergies, your prescriber may recommend using a combination of a nasal steroid and an oral antihistamine. But research suggests this combination typically doesn’t provide that much extra relief for most people. Instead, some experts recommend using a nasal steroid and a nasal antihistamine. This combination can provide more symptom relief than either does by itself.
You may also find added congestion relief by taking an oral decongestant, such as Sudafed, with other allergy medications. However, decongestants may also cause side effects, such as:
Dry mouth
High blood pressure
Fast heartbeat
Headache
Shakiness
Trouble sleeping
Some individuals, such as older adults or people with heart problems, may experience more side effects when taking many allergy medications. Make sure to discuss the risks and benefits of combining these treatments with your prescriber or pharmacist.
Take our quiz: Allergy medications
Is it a good idea to change the type of allergy medication you’re taking?
If you feel like your allergy medication has stopped working, you’re not alone. This is a relatively common problem. But changing medications may not be the right solution.
Although some people say that switching to a different antihistamine provides better relief, studies have not shown that antihistamines stop working when people take them for a long time. It’s not common to develop tolerance to an allergy relief medication. For instance, research shows newer antihistamines like Zyrtec provide the same amount of relief 180 days (about 6 months) after first starting them.
If you experience more allergy symptoms while taking your antihistamine, it may mean that you developed a new allergy. Therefore, you should speak with a healthcare professional to discuss potentially adding or switching to a different medication, such as a nasal spray.
Are there ways to manage allergy symptoms without medication?
An important part of managing allergies is avoiding allergens that may trigger symptoms. Common allergens include:
Pollen
Pet dander
Mold
Dust mites
Cigarette smoke
A sinus flush, also known as nasal irrigation, may be helpful in clearing out potential allergens. It involves flushing out the nose with a salt solution using a device like a neti pot. However, you should only use distilled or sterile water (rather than tap water) to avoid harmful infections.
Having good air filtration within your home is also crucial in managing seasonal allergies. Cleaning and replacing the air filters in your home’s heating, ventilation, and air conditioning (HVAC) systems or using portable room air purifiers can lower the amount of allergens and improve allergy symptoms.
Frequently asked questions
Sometimes, but it depends on the active ingredients in each product. Many cold medications — especially “nighttime” products — contain an antihistamine. You wouldn’t want to combine these products with an allergy medication that also includes an antihistamine. Read the OTC label of your selected products to make sure you’re not duplicating medications. If you’re unsure whether a combination is safe, ask a pharmacist.
Yes, you can mix allergy medications with Tylenol (acetaminophen). But be sure to carefully read the OTC labels of your products. Some Tylenol-brand products contain an antihistamine, such as Tylenol PM (acetaminophen / diphenhydramine). You wouldn’t want to take these products with an allergy medication that also has an antihistamine.
It’s not recommended to drink alcohol while taking oral antihistamines or oral decongestants. Alcohol can worsen side effects that these medications may cause. But it’s likely safe to drink if you’re taking non-oral allergy medications, such as nasal sprays or eye drops. Only small amounts of allergy medications reach your bloodstream when you apply it to your nose or eyes.
The bottom line
Some people may need to combine different allergy medications to treat their allergy symptoms. It’s safe for most people to take allergy medications that are in different classes. For example, nasal steroids, such as Flonase (fluticasone propionate), and oral decongestants, such as Sudafed (pseudoephedrine), can be taken together. However, you shouldn’t combine multiple oral antihistamines, such as Zyrtec (cetirizine) and Benadryl (diphenhydramine), without a healthcare professional’s OK. Make sure to discuss this with your prescriber or pharmacist to determine the best allergy medication to treat your symptoms.
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