Benadryl With Prednisone Interaction

In our latest question and answer, the pharmacist discusses the potential drug interaction between Benadryl (diphenhydramine) and prednisone.


I am taking prednisone 10MG. Can I take with Benadryl (diphenhydramine) too?

Asked by Cristita On Jul 22, 2018

Answered by
Medical Content Reviewed By PharmacistAnswers Staff

On Jul 22, 2018

There are no drug interactions between Benadryl (diphenhydramine) and prednisone. In fact, these two medications are often used together for certain indications including allergic reactions. Below we will discuss further information about these two drugs.


Information About Benadryl

Benadryl is a first-generation antihistamine. Antihistamines are widely used for self-care of allergy symptoms including runny nose, watery eyes, sneezing, and itching of the nose, throat, or eyes. Benadryl may also be used for symptoms of the common cold, allergic reactions, occasional insomnia, and more.

Because Benadryl is a first-generation antihistamine, it is more likely to cause sedation and drowsiness. Other first-generation antihistamines include Dramamine (dimenhydrinate), Chlor-Trimeton (chlorpheniramine), Tavist (clemastine), and Phenergan (promethazine), among others. These medications cross the blood-brain barrier and have CNS effects like drowsiness and dizziness.

First generation antihistamines can also cause urinary retention, GI upset, and blurry vision. The first generation antihistamines are also listed as medications to avoid in elderly adults by the Beers Criteria due to the increased risk of confusion, dry mouth, and drowsiness.

Second generation antihistamines include Claritin (loratadine), Cetirizine (Zyrtec), and Allegra (fexofenadine) and are much less sedating. These antihistamines are generally only used for treatment of allergy symptoms, whereas Benadryl can be used for a variety of reasons including allergies, insect bites, poison ivy, sleep, and motion sickness.


Information About Prednisone

Prednisone is the most commonly prescribed oral corticosteroid. Prednisone was first approved by the FDA in 1955. Corticosteroids work by suppressing inflammation and the immune response. Prednisone and other corticosteroids have a variety of indications including asthma, COPD, general inflammatory conditions, and many more.

Short term use of corticosteroids are generally well tolerated. Long term use may cause a wide range of side effects including impaired wound healing, muscle weakness, bone fractures, and hyperglycemia. After long term use, abrupt discontinuation of corticosteroids should be avoided. Tapering the dose may be necessary after lengthened therapy.


To conclude, diphenhydramine and prednisone may be taken together as there are no drug interactions between the two commonly used medications. 

About the Pharmacist

Dr. Kevin Davis Pharm.D

Dr. Kevin Davis is a licensed pharmacist with experience in retail and hospital pharmacy. He graduated from the University of Florida with a Doctor of Pharmacy degree in 2015 and a Master of Healthcare Administration degree from Adventist University in 2017. He is also a Board Certified Pharmacotherapy Specialist since 2016.

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