Benadryl is the brand name. Diphenhydramine is the generic name. Numerous other generic products also exist. Benadryl is an antihistamine used to treat hay fever and allergies.
Benadryl is a nonprescription (over-the-counter) antihistamine. It is an older antihistamine and inhibits type 1 histamine receptors, as well as other, unrelated receptors, in both the brain (central nervous system) and throughout the body, thereby increasing the incidence of sedation. Because of its strong sedative effect, it is rarely used for daily treatment of allergies. Antihistamines compete with histamine for histamine receptor sites. By occupying the histamine receptor sites, they prevent histamine from its actions.
Benadryl is indicated for adults and children 2 years or older to temporarily relieve symptoms caused by hay fever and allergies (runny nose, sneezing, itchy/watery eyes, scratchy nose or throat). It is available in a variety of forms, including tablets, and syrup. Benadryl may also be administered as an injection for serious allergic reactions.