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).


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?

Asked by Tess On Mar 21, 2023

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Mar 21, 2023
Last updated Jun 14, 2024

Key points

  • There is no known drug interaction between Benadryl (diphenhydramine) and Tessalon (benzonatate), but both may cause drowsiness. Their use together could enhance this side effect.


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 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 mechanism of action 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.


About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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