Benadryl, also known as Diphenhydramine, is an antihistamine drug. It is usually found as a crystalline, white powder and is soluble in water and alcohol. Diphenhydramine is typically used for treating allergic reactions.
In the body, histamine is released when one suffers through an allergic reaction or even viral infections. The histamine then binds to cell receptors, triggering changes in the cell that lead to allergy symptoms such as itching and sneezing.
As an antihistamine drug, diphenhydramine competes against the histamine for the cell receptors. The antihistamine not only prevents histamines from binding and stimulating the cells but while doing so, it also binds to the receptors—they do not stimulate the cells, therefore allergy symptoms will not show.
Benadryl was discovered by George Rieveschl, who took part in many experiments with focus on relieving muscle pain at University of Cincinnati. Benadryl is an antihistamine drug that used for treating people who suffer with allergy. Benadryl was first available through prescription in 1946. Later in 1980s, it was approved as over-the-counter drug.
Benadryl contains the histamine-blocker diphenhydramine. This drug will help patients to recover from common symptoms: sneezing, watery eyes, runny nose, and sore throat. One application of Benadryl is Benadryl Chesty Cough & Nasal Congestion: a drugs that is used to relieve the symptoms of chesty cough and cold.
Side Effects 
Do not use this drugs if you are currently treating with depression, heart condition, blood pressure, and behavioral disorder. As many other drugs, Benadryl does have some common side effects:
- dry mouth
- difficulty urinating.
"Benadryl (Diphenhydramine) Drug Information". RXList. 2009. Retrieved March 6, 2009
Ohio History central: Benadryl; accessed Jan. 5, 2011
Benadryl for the Family Chesty Cough & Nasal Congestion Oral Liquid ; accessed Oct. 13, 2011
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