NCIt definition : A first generation monoethanolamine with antihistaminic property. Ethanolamine competes
with free histamine for binding at the histamine (H)-1 receptor thereby acting as
an inverse agonist that combines with and stabilizes the inactive form of the H1-receptor
thereby shifting the equilibrium toward the inactive state. This leads to a reduction
of the negative symptoms brought on by H1-receptor binding.;