Azelastine hydrochloride tablets have the effect of anti-allergy. Azelastine hydrochloride tablets is a kind of western medicine, the main ingredient of the drug is azelastine hydrochloride, after entering the human body can be metabolized out of a special metabolite, this metabolite can antagonize the histamine H1 receptor, there is an antihistamine effect, so as to play the efficacy of the antiallergic effect, clinically commonly used in urticaria, allergic rhinitis, and other patients of the treatment. The drug has not been found serious adverse reactions, common adverse reactions are drowsiness, dizziness, dry mouth, nausea, fatigue and so on. It should be noted that azelastine hydrochloride allergy is prohibited, and should not be applied to pregnant and lactating women; children under 12 years of age should not be applied; the drug can not be taken at the same time with other drugs to inhibit the central nervous system. If patients have the need for medication, they should follow the guidance of a professional physician, so as not to blindly use the drug, resulting in adverse consequences.