Rufapin, Rupatadine is a second-generation antihistamine and PAF (platelet-activating factor) antagonist used primarily to treat symptoms of allergic rhinitis and urticaria (hives). Unlike first-generation antihistamines, rupatadine is less likely to cause sedation because it does not readily cross the blood-brain barrier. Mechanism of Action Rupatadine works by blocking the action of histamine ..