NCIt definition : An alkylamine derivative with anticholinergic and sedative properties. Dexbrompheniramine
is a histamine H1-receptor antagonist that competes with histamine for the H1-receptor
sites on effector cells in the gastrointestinal tract, blood vessels and respiratory
tract. The antagonistic action of this agent blocks the activities of endogenous histamine,
which subsequently leads to temporary relief from the negative histamine-mediated
symptoms of allergic reaction such as bronchoconstriction, vasodilation, increased
capillary permeability and spasmodic contractions of gastrointestinal smooth muscle.;