Patanol

Patanol works by preventing the actions of histamine, which is a substance produced by the body as part of its defense mechanisms. Histamine is stored in cells called mast cells, in almost all tissues of the body. In hayfever, histamine causes eye symptoms such as inflammation, redness and itching by acting on H1 receptors in the eyes. Olopatadine blocks the H1 histamine receptors in the eyes, and thus stops these effects of histamine.