Benadryl allergy oral solution

Benadryl allergy oral solution contains the active ingredient cetirizine, which is a type of medicine called a non-sedating antihistamine. (NB. Cetirizine is also available without a brand name, ie as the generic medicine.) Cetirizine works by preventing the actions of histamine. Histamine is a substance produced by the body as part of its defence mechanisms. It is stored in cells called mast cells, in almost all tissues of the body. When the body reacts to a foreign substance (known as an allergen, eg flower pollen), the mast cells stimulated by the allergen release their stores of histamine. The released histamine then binds to its receptors (H1 receptors), causing a chain reaction that results in allergic symptoms. It causes an increase in blood flow to the area of the allergy, and the release of other chemicals that add to the allergic response.