[{"from": "human", "value": "Describe this molecule. [C][N][C][C][C][C][Branch1][Branch1][C][C][Ring1][#Branch1][N][C][=Branch1][C][=O][C][=C][C][=C][C][=C][Ring1][=Branch1][C][=Branch1][Ring2][=N][Ring1][O][C][C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][Cl].[Cl]"}, {"from": "gpt", "value": "The molecule is the hydrochloride salt form of azelastine, a phthalazinone derivative with antihistaminergic activity. Azelastine hydrochloride competes with histamine for the H1 receptor, thereby diminishing the actions of histamine on effector cells and decreasing the histamine-mediated symptoms of allergic reaction, such as bronchoconstriction, vasodilation, increased capillary permeability and spasmodic contractions of gastrointestinal smooth muscle."}]