Cetirizine hydrochloride drops, an antihistamine, is an H1 receptor antagonist and is more suitable for use in children. It is mainly used for seasonal or perennial allergic rhinitis, allergic conjunctivitis, or other skin conditions caused by allergies, such as acute and chronic urticaria, allergic dermatitis, acute and chronic eczema, and pruritus. It can also be used for pruritic symptoms caused by other skin diseases, such as pruritus in psoriasis vulgaris and pruritus caused by diabetes mellitus. Some patients may experience mild adverse reactions after oral administration, such as sleepiness, drowsiness, headache, dizziness, dry mouth and gastrointestinal reactions.