Antihistamines, available in a tablet format, block the receptors of histamine that is one of the inflammatory substances that cause allergy symptoms. FLONASE Allergy Relief is applied to the nose and works differently than an antihistamine. FLONASE is a nasal spray that works by helping to control 6 of the key inflammatory substances (including histamine) your body produces that cause allergy symptoms. *
*Mechanism vs. most OTC allergy pills. FLONASE® acts on multiple inflammatory substances (histamine, prostaglandins, cytokines, tryptases, chemokines and leukotrienes). The exact number and precise mechanism are unknown.