Bilastine is a selective peripheral H1 histamine receptor antagonist that competitively inhibits histamine binding to H1 receptors on effector cells in the respiratory tract, skin, and other tissues. By blocking these receptors, bilastine prevents histamine-mediated allergic symptoms such as vasodilation, increased vascular permeability, edema, pruritus, and bronchoconstriction. It does not cross the blood-brain barrier significantly, resulting in minimal sedation.