Can You Take Prednisone With Benadryl?
Written By Kobi Nathan, Pharm.D., M.Ed., CDP, BCGP, AGSF
Sleep Disorders
May 20, 2023

Can You Take Prednisone With Benadryl?

Yes, you can take prednisone and Benadryl together safely, as there is no known interaction between them. However, each medication comes with its own set of adverse effects.

Read on to learn more…

How does Benadryl work?

It’s crucial to grasp how Benadryl works, as this knowledge could impact your health and well-being significantly. This is particularly important if you are an older adult! More on this later…

Benadryl, also known as diphenhydramine, is an oral over-the-counter antihistamine that belongs to the class of drugs called histamine blockers. These medicines work by inhibiting the release of histamines – substances produced by your body during an allergic reaction or inflammation.

Histamines cause symptoms such as itching, sneezing, runny nose, and watery eyes. By blocking the action of histamines in your body, Benadryl helps alleviate these uncomfortable symptoms and provides relief.

Knowing about antihistamine alternatives can be beneficial for those who need relief from allergy symptoms but might not be able to take Benadryl due to sensitivity to this particular medication.

Some popular alternatives include cetirizine (Zyrtec), loratadine (Claritin), and fexofenadine (Allegra). These medications are considered second-generation antihistamines and tend to have fewer side effects than first-generation options like Benadryl.

Second-generation antihistamines were formulated to last longer in the system, which means you won’t need to take them as often throughout the day.

That said, Zyrtec is actually sedating, despite being a second-generation agent, and should be used with caution.

I always advise my older adult patients to stop taking it and recommend they take Allegra instead, which is not as sedating.

More on side effects later in this article…

How does prednisone work?

Prednisone, a prescription corticosteroid, works by suppressing your immune system and reducing inflammation throughout your body. This powerful medication helps combat allergy triggers by preventing the release of substances that cause inflammation.

Moreover, prednisone can provide relief from symptoms such as swelling, itching, and redness caused by allergies or inflammatory conditions like asthma or rheumatoid arthritis.

It’s important to consult with your healthcare provider before combining these two medications to ensure proper dosage adjustments are made if necessary. By doing so, you can help others breathe easier knowing they’re taking the right course of action in treating their allergy-related discomforts while minimizing potential side effects from drug interactions.

Potential Interactions and Side Effects

Drug synergy is an important factor to consider when taking multiple medications, as it refers to the interaction between two or more drugs that result in either enhanced or diminished effects.

In the case of prednisone and Benadryl, both drugs are used to treat allergic reactions, but they work through different mechanisms: Prednisone is a corticosteroid that reduces inflammation, while Benadryl is an antihistamine that blocks histamines from causing symptoms like itching and swelling.

Generally speaking, there aren’t any major interactions between prednisone and Benadryl; in fact, they can be taken together under your doctor’s supervision for short-term relief of severe allergic reactions. However, it’s essential to be aware of the possible side effects each drug may cause individually.

Prednisone adverse effects

Prednisone has several potential side effects such as mood swings, weight gain, high blood pressure, osteoporosis (bone loss), and increased susceptibility to infections.

Click on the video below to watch the known and not-so-known adverse effects of Corticosteroids.

You may be surprised by some of them. If your doctor has prescribed you a course of steroid therapy, then it is for a clear and necessary medical indication.

Trust your doctor’s judgment, but don’t hesitate to ask pointed questions about possible negative effects. It is your right to know and empower yourself with information!


Benadryl adverse effects (anticholinergic effects)

On the other hand, common side effects of Benadryl include worsening of dementia, increase your risk for falls and injuries due to drowsiness and dizziness, dry mouth, and constipation.

Watch the short video below to learn more about anticholinergic side effects:

It’s always best to consult with your healthcare provider before starting any new medication regimen or combining medications – they can help ensure that you’re using these powerful tools in a safe manner to effectively manage your allergies without exposing yourself to unnecessary risks.

Many seemingly benign prescription and OTC drugs can result in serious consequences for you, especially if you are an older adult.

This is because of how your body changes as you get older and how you respond to medications. You are also more sensitive to drug interactions as an older adult.

I discuss all of these important concepts in my articles on Polypharmacy and the 2023 Updated Beers Criteria for Inappropriate Medications in Older Adults.

I highly recommend you read these posts – they could be life-changing for you or your older loved ones!

The video below from my YouTube channel discusses how inappropriate medications can be safely eliminated through thoughtful analysis:

When combining medications may be appropriate

There are instances where it might be necessary to combine these medications, and understanding the appropriate scenarios can help you navigate allergy treatment effectively.

Combining the benefits of prednisone, a corticosteroid that reduces inflammation, and Benadryl, an antihistamine that provides relief from allergy symptoms like sneezing, itching, and hives, can be helpful in certain situations.

Appropriate situations may include severe allergic reactions or when a healthcare provider has deemed it necessary due to your specific medical history and current conditions.

Before deciding to take both prednisone and Benadryl together, consult with your healthcare provider or pharmacist to discuss the potential risks and benefits of this combination.

They’ll consider factors such as your age, overall health condition, duration of treatment needed for each medication, as well as any other medications you may currently be taking.

Ensuring that you follow their advice will allow you to make informed decisions about your allergy treatment plan while prioritizing safety and effectiveness in managing your symptoms.

When combining medications may be inappropriate

Although prednisone can be combined with diphenhydramine, many other drugs cannot be. Combining other antihistamines such as NyQuil or other anticholinergic medications can be dangerous, leading to anticholinergic toxicity.

I discuss this extensively in my article, can NyQuil and Benadryl be taken together?

If you are taking hydroxyzine for anxiety, taking any antihistamine with it is not recommended. You should definitely talk to your doctor about how best to manage your anxiety and manage your allergies at the same time.

A final word about anticholinergic effects – this seminal work by Coupland and colleagues verifies that taking such agents chronically can lead to an increased risk of dementia.

Frequently Asked Questions

Can taking Prednisone and Benadryl together cause any long-term effects on the body?

While considering the potential long-term effects of taking prednisone and Benadryl together, it’s important to be aware of possible prednisone and Benadryl adverse effects.

Although these medications are often used in conjunction to treat a variety of conditions, you should consult your healthcare provider about the specifics of your situation. They can help determine if combining these drugs is appropriate for your needs and give guidance on how to safely manage any potential risks.

Are there any specific age restrictions for combining Prednisone and Benadryl, especially in children or elderly patients?

When considering age-based interactions and pediatric precautions for combining medications, it’s crucial to consult with a healthcare professional before administering prednisone and Benadryl to children or elderly patients.

Both drugs have specific dosing guidelines based on age and weight, and potential side effects may vary among different age groups.

Children are often more susceptible to certain side effects, while elderly patients might experience increased sensitivity or reduced ability to metabolize the medications.

By taking appropriate precautions and seeking expert advice, you’ll be better equipped to help your loved ones with their medical needs safely and effectively.

Can pregnant or breastfeeding women safely take Prednisone and Benadryl together?

Navigating the waters of medication use during pregnancy and breastfeeding can feel like sailing through a storm, but it’s important to weigh the potential risks and benefits for both you and your baby.

When considering taking prednisone and Benadryl together, pregnancy risks include potential harm to the developing fetus, especially if taken during the first trimester.

Long-term prednisone use during pregnancy has been linked to premature birth (before 37 weeks) and low birth weight (less than 5 pounds, 8 ounces).

Breastfeeding considerations should also be taken into account, as both medications can pass into breast milk.

Always consult with your healthcare provider before combining these drugs or starting any new medication regimen during pregnancy or while breastfeeding; they’ll help guide you on the safest course toward ensuring optimal health for both you and your little one.

How do the dosages of Prednisone and Benadryl affect the efficacy of the combined treatment for allergies and inflammation?

Finding the right dosage balance for allergy interactions when combining prednisone and Benadryl is crucial to ensure their effectiveness in treating your allergies and inflammation.

It’s important to follow your healthcare provider’s recommendations, as they will take into account your specific condition and medical history.

Generally, a lower dose of both medications may be prescribed initially to assess how well they work together and minimize potential side effects.

Gradual adjustments may be made based on your response, but always remember that self-adjusting dosages can lead to complications or reduced efficacy.

By working closely with your healthcare provider, you can achieve optimal results while minimizing risks, ultimately helping you effectively manage your symptoms and serve others with confidence.


In the end, mixing prednisone and Benadryl is like trying to put out a fire with two different types of extinguishers. Both can help calm your symptoms, but they work in distinct ways that can complement each other.

Always consult your healthcare provider before combining these medications. They’ll be able to guide you on the best course of action for your specific situation, ensuring you get the relief you need without any unnecessary risks.

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