diphenhydramine

American  

[dahy-fen-hahy-druh-meen] / ˌdaɪ fɛnˈhaɪ drəˌmin /

noun

Pharmacology.

1. a white, crystalline, antihistaminic compound, C 17 H 21 NO, used orally, topically, and parenterally, especially for allergies.

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Etymology

Origin of diphenhydramine

First recorded in 1945–50; diphen(yl) + hydr- ² + amine

Example Sentences

Anticholinergics also include diphenhydramine, the active ingredient in over-the-counter products like Benadryl.

From The Wall Street Journal • Jan. 8, 2026

And while sedating antihistamines like diphenhydramine might help you sleep at night, they don't treat the cough itself.

From BBC • Dec. 3, 2025

The over-the-counter antihistamines I used to take, which contain diphenhydramine, “were never really systematically studied for their effects on sleep,” Dr. Krystal said.

From New York Times • Apr. 7, 2022

Medical solutions include an antihistamine, such as diphenhydramine, as needed for the itching that can result from mild eczema and topical prescription steroid cream for more serious cases.

From Washington Post • Feb. 6, 2011

Medical solutions range from an antihistamine such as diphenhydramine as needed for the itching that can result from mild eczema to topical prescription steroid cream for more serious cases.

From Seattle Times • Jan. 31, 2011