Can You Take Benzonatate With Benadryl?

In our latest question and answer, our pharmacist discusses whether or not Benadryl (diphenhydramine) can safely be taken with Tessalon (benzonatate).

2 min read Updated Jun 2026 Read by 8,159 people
Can You Take Benzonatate With Benadryl?
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Tess asked

I was recently prescribed Tessalon for a cough I have. I am getting over bronchitis. I want to take Benadryl at night to help me sleep. Are they safe together?

Mar 21, 2023
The quick answer
  • There is no known interaction between benzonatate and Benadryl, and they are considered safe to take together.
  • Both medications can cause drowsiness, so you should avoid driving or activities requiring mental alertness when taking them together.
  • Benzonatate works by numbing the cough reflex and typically begins working within 15-20 minutes, while Benadryl is an antihistamine used for allergies and sleep.
A quick summary of Dr. Brian Staiger, PharmD's full answer below, condensed by AI from that answer only (not from any outside source). The pharmacist's answer is the source of record.
Medications in this answer — tap to explore

Answer

Thanks for reaching out and great question! There is no known interaction between Benadryl (diphenhydramine) and Tessalon (benzonatate). They are considered safe to take together.

In the next sections, I discuss each drug in more detail.

What Is Tessalon?

Tessalon (benzonatate) is a medication that is commonly used to treat coughs associated with bronchitis or other respiratory conditions.

It is thought to work primarily by numbing the cough reflex in the lungs and airways, which can help alleviate persistent coughing.

It has a quick onset of action, beginning to work approximately 15-20 minutes after taking a dose, and typically lasts around 4-8 hours.

Benzonatate is generally very well tolerated, and has few, if any, serious drug interactions. In fact, most resources report benzonatate has no clinically significant drug interactions.

What Is Benadryl?

Benadryl (diphenhydramine) is a 'first-generation' antihistamine and is commonly used for allergies and sleep issues (due to its sedative effects).

It works by blocking the action of histamine, which is a chemical that is released by the body in response to allergens. This can help relieve symptoms such as sneezing, itching, and runny nose.

First-generation antihistamines are noted for their sedative effects and relatively short duration of action when compared to their newer, second-generation counterparts, like Allegra (fexofenadine) and Claritin (loratadine).

Taking Tessalon And Benadryl Together

Tessalon (benzonatate) and Benadryl work differently and are not thought to interfere with one another. Neither is known to affect the other's mechanism of action or metabolism or metabolism.

However, it is important to note that, although benzonatate is relatively well-tolerated overall with only minor side effects reported, it can cause dizziness and drowsiness.

Since Benadryl has fairly strong sedative effects, when combined with benzonatate, there is a risk of additive drowsiness.

Therefore it is important to avoid activities that require you to be mentally alert, such as driving a car, when taking both medications.

Final Words

I hope you found this helpful! Reach back out anytime.

References & sources
  1. Benzonatate Monograph — PubChem
  2. Diphenhydramine Monograph — PubChem
Glossary — Terms in This Answer
Diphenhydramine
The active ingredient in Benadryl, a type of antihistamine medication used to treat allergies and sleep issues.
Benzonatate
The active ingredient in Tessalon, a medication used to treat coughs by numbing the cough reflex.
Antihistamine
A medication that blocks the action of histamine, a chemical the body releases in response to allergens.
Histamine
A chemical released by the body in response to allergens that causes allergy symptoms like sneezing and itching.
First-generation antihistamine
An older type of antihistamine known for causing drowsiness and having a shorter duration of action than newer versions.
Sedative effects
The calming and sleep-inducing properties of a medication.
Additive drowsiness
Increased sleepiness that occurs when two medications that each cause drowsiness are taken together.
Bronchitis
An inflammation of the airways in the lungs that commonly causes persistent coughing.
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Dr. Brian Staiger, PharmD
About the pharmacist

Dr. Brian Staiger, PharmD

Clinical Pharmacy

Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified

Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...

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