definition
An antihistamine and anticholinergic drug that blocks the effect of histamine at H1 receptor sites, relieving allergy symptoms. Diphenhydramine also reduces smooth muscle contraction, increases heart rate, and sedates the user by blocking muscarinic acetylcholine receptors (mAChRs).
Mild cases of hives are treated with antihistamines, such as diphenhydramine (Benadryl).
Benadryl (and others) includes the active ingredient diphenhydramine and is not for use in children under age two without a doctor's permission.
An antihistamine such as diphenhydramine is usually given by mouth or injection to diminish the histamine reaction.
The generic name for two common antihistamines are chlorpheniramine and diphenhydramine.
Antihistamines such as diphenhydramine (Benadryl) can help relieve itching caused by hives but will not relieve itching from other causes.
Also, the antihistamine diphenhydramine hydrochloride (Benadryl) may help to relieve itchy eyes.