Medically reviewed by Daniel Combs, MD Benadryl (diphenhydramine) is an over-the-counter (OTC) antihistamine commonly used to ...

(Photo Credit: E+/Getty Images) Getting the dosage right is important because most Benadryl tablets are intended for humans. Dogs are smaller than people, so they need less Benadryl than a person.

She asked for Benadryl, which reduces swelling by blocking histamines, chemicals our body produces when an allergen is present. A box of 24 tablets of Benadryl can cost as little as $6 at CVS or $ ...