Can you take Benadryl with amoxicillin?

In this article:

• Can you take Benadryl with amoxicillin?
• What happens if you take Benadryl and amoxicillin together?
• When would you need to take amoxicillin and Benadryl at the same time?
• Safety

In this article

• Can you take Benadryl with amoxicillin?
• What happens if you take Benadryl and amoxicillin together?
• When would you need to take amoxicillin and Benadryl at the same time?
• Safety

Benadryl (with the active ingredient diphenhydramine Hcl) is an allergy medication and over-the-counter antihistamine. It works as an histamine receptor antagonist against histamine receptors, blocking histamine from binding and preventing allergic reactions. It can treat hay fever, allergy symptoms, cold symptoms, and insomnia. People can take it as a capsule, tablet, orally dissolving film, or liquid.

Amoxicillin is a generic prescription medication in the penicillin family. Found in the form of a tablet, capsule, and liquid suspension, this penicillin antibiotic can treat a variety of bacterial infections (not viral infections) by killing a broad spectrum of bacteria. 

These medicines can typically be taken together if needed.

Can you take Benadryl with amoxicillin?

You read that good news right: These two medications can be combined, according to Dr. Raj Dasgupta, MD, chief medical advisor for Fortune Recommends. He says this goes for lower and higher doses as long as patients listen to their healthcare provider’s directions around the use.

Dr. Danielle Kelvas, MD, a primary care physician at the HCG Institute, agrees. “They do not have known drug interactions,” she says. “This remains true regardless of dosage and other factors, like age and condition, unless specified by a healthcare provider.”

Dr. Dasgupta says this general safety factor extends to different antibiotics when combined with Benadryl, but still double-check with a medical professional or pharmacist.

The same goes for a specific antibiotic—amoxicillin—with allergy meds in general. “Most over-the-counter allergy medications can also be safely combined with amoxicillin,” Dr. Dasgupta says.

Dr. Kelvas agrees that more general combinations are safe and can even be a smart move. “This can be helpful in treating symptoms associated with infections, such as allergic reactions or sinus congestion,” she adds.

What happens if you take Benadryl and amoxicillin together?

As mentioned, taking Benadryl with amoxicillin is generally safe and shouldn’t result in many or any side effects as a combination.

The only thing Dr. Kelvas wants to warn about is drowsiness. “Both drugs can cause drowsiness, so taking them together may increase this effect,” she says. “Always monitor your body’s response when taking new medication combinations.”

Dr. Dasgupta adds that each medicine has its own set of potential side effects. 

Benadryl’s side effects include: 

• Allergic reactions
• Sudden eye pain or change in vision
• Trouble urinating 
• Constipation
• Drowsiness
• Dry mouth
• Headache
• Upset stomach

The most common side effects of amoxicillin include: 

• Rash
• Diarrhea
• Headache
• Nausea
• Vomiting
• Stomach pain
• Tongue discoloration
• Yeast infection
• Elevated liver enzymes
• High white blood cell counts

Additionally, note that amoxicillin-clavulanate (compared to just amoxicillin) may cause more gastrointestinal side effects, according to a 2021 study in the Journal of the American College of Emergency Physicians Open.

In rare cases, people may experience adverse effects such as superinfections, Clostridium difficile-associated diarrhea, liver problems, blood disorders, seizures, swelling of brain and spinal cord membranes, and severe allergic reactions.

So again, don’t combine these medications without checking with a medical professional—especially in the presence of pre-existing health conditions, Dr. Dasgupta says. “It’s also important to monitor for any unusual symptoms or allergic reactions, as even generally safe combinations can cause reactions for some people,” he adds.

Some other medications should be avoided with Benadryl, such as blood pressure medications and antidepressants. On that note, certain medications must be avoided when taking amoxicillin, too, such as probenecid and certain other antibacterials (these are only a few examples). Not drinking alcohol while on these medications is another smart idea.

Dr. Kelvas adds that antihistamines may mask symptoms of allergic reactions to antibiotics.

Certain adverse reactions call for immediate treatment and/or even an emergency room trip. If someone experiences serious side effects—such as an itchy rash or hives, swelling, severe dizziness, or difficulty breathing—they should seek immediate medical attention, these doctors say.

Speaking of rashes and the antibiotic amoxicillin, it’s important to note that a penicillin allergy affects 1% of people (though 10% report it). Since amoxicillin is a type of penicillin, it may not be the best thing for all patients. To diagnose this, a healthcare provider will administer a skin test. A positive result indicates a likelihood of a penicillin allergy, whereas a negative result means a patient is usually not at risk for the allergy.

An amoxicillin rash on the skin isn’t always a sign of an allergic reaction, however. Signs of a true allergic reaction include a sudden rash within two hours of the first amoxicillin dose, breathing or swallowing difficulties, and very itchy hives. This is caused by the immune system thinking the medicine is a foreign invader. On the other hand, a non-allergic skin rash is a flat, red patch that may be slightly raised and doesn’t cause other problems.

Once a patient ensures it’s okay for them to take amoxicillin and an allergy medicine, it’s okay to take them at the same time, according to these doctors. 

“Benadryl is typically dosed once every 24 hours, whereas amoxicillin is taken multiple times a day, but there is no contraindication for taking them together,” Dr. Kelvas says. 

Dr. Dasgupta adds that in some cases, people may prefer to take Benadryl at night since it can cause drowsiness.

When would you need to take amoxicillin and Benadryl at the same time?

With that said, when might someone need to take these medicines in conjunction?

“Someone might need to take both Benadryl and amoxicillin if they are treating an infection with amoxicillin and also experiencing allergy symptoms, such as seasonal allergies,” Dr. Dasgupta says. 

Symptoms of allergies include a runny nose, itchy eyes, sneezing, headache, sore throat, and cough.

Dr. Kelvas agrees. “This can help in managing symptoms like nasal congestion, allergic sinusitis, or hives associated with infections,” she adds.

Is it safe to take Benadryl and amoxicillin together? 

To conclude, yes: It is safe to take Benadryl and amoxicillin together, regardless of dose. Side effects may occur—such as allergic reactions and gastrointestinal distress—but they’re probably due to one of the individual medications, rather than the combination. 

While this is generally true, it’s better to be safe than sorry. Talking to a healthcare provider before changing medications or dosages in any way is important.