<p>Rupatadine is a long-acting, non-sedative antagonist of histamine H1-receptors. It also antagonizes the platelet activating factor (PAF). Both histamine and PAF cause broncho constriction which leads to an increase in the vascular permeability and act as a mediator in the inflammatory process. With the dual mode of action, Rupatadine shows better therapeutic effect than an isolated antihistamine. Rupatadine possesses other anti allergic properties such as the inhibition of the degranulation of mast cells induced by immunological and non immunological stimuli and inhibition of the release of cytokines, particularly of the tumor necrosis factor alpha (TNF &alpha;) in human mastocytes and monocytes.</p>