Olotadine hydrochloride mainly has the effect of anti allergy. First, it has a certain antagonistic effect on histamine receptor, which is a substance related to allergic reaction. Olotadine blocks the effect of histamine on allergic reaction by antagonizing the combination of histamine and its receptor. Secondly, olotadine also has a certain inhibitory effect on chemical media, such as leukotriene and other allergy related chemicals. Olotadine can play a certain inhibitory role, thus inhibiting the occurrence of allergic reactions. In clinical practice, olotadine hydrochloride tablets can be mainly used for allergic rhinitis and can improve the symptoms of allergic rhinitis. In addition, it can also be used for skin allergic diseases, such as urticaria, skin itching, eczema or other allergic skin diseases. In a word, olotadine hydrochloride tablets mainly have anti allergic effects.