Cetirizine is mainly used for the treatment of seasonal or perennial allergic rhinitis and urticaria. Loratadine is mainly used to relieve the symptoms of allergic rhinitis, chronic urticaria, pruritic dermatoses and other allergic skin diseases. Cetirizine, the main ingredient is cetirizine hydrochloride. It is generally used clinically for the treatment of seasonal or perennial allergic rhinitis and urticaria. Loratadine, the main ingredient is loratadine. Clinically, it is generally used in patients with allergic rhinitis as well as chronic urticaria, itchy skin disease and other allergic skin disease symptoms of relief treatment. Patients taking cetirizine may experience adverse reactions such as headache, dry mouth, drowsiness, etc. It is also contraindicated in allergic patients, pregnant women and those with renal dysfunction. In addition to the above adverse reactions, loratadine may also cause cardiovascular system disorders and gastrointestinal system discomfort and other symptoms, allergy is prohibited, people with impaired hepatic function, pregnant women, lactating women, children under the age of 6 years should be cautious. The use of drugs must be used correctly under the guidance of a professional doctor, do not blindly use drugs on their own.