In English | En español
Questions About Cancer? 1-800-4-CANCER

NCI Drug Dictionary


diphenhydramine hydrochloride 
The hydrochloride salt form of diphenhydramine, an ethanolamine and first-generation histamine antagonist with anti-allergic activity. Diphenhydramine hydrochloride competitively blocks H1receptors, thereby preventing the actions of histamine on bronchial smooth muscle, capillaries, and gastrointestinal (GI) smooth muscle. This prevents histamine-induced bronchoconstriction, vasodilation, increased capillary permeability, and GI smooth muscle spasms. Check for active clinical trials or closed clinical trials using this agent. (NCI Thesaurus)
US brand names:Benadryl
SK-Diphenhydramine
Foreign brand names:Bendylate
Eldadryl