doxylamine

:  an antihistamine derived from pyridine that is typically used in the form of its succinate C₁₇H₂₂N₂O·C₄H₆O₄ to treat respiratory symptoms of the common cold and allergies, to induce sleep in the treatment of insomnia, and in combination with pyridoxine hydrochloride to control nausea and vomiting associated with pregnancy