The dosage of Cetirizine Hydrochloride Drops needs to be treated separately under the guidance of a doctor according to different patients and different conditions, and its dosage is too complicated to be summarized briefly, and the specific dosage of the manual is as follows. 1.1～2 years old children once a day, each time 0.25ml. 2. For the treatment of seasonal allergic rhinitis in children aged 2 to 6 years, it is necessary to use the medicine under the guidance of a doctor or in accordance with the twice a day, each time 0.25 ml; or once a day, each time 0.5 ml of medicine. 3. When using Cetirizine Hydrochloride Drops for adults or children over 6 years old, follow the doctor’s instructions or follow the dosage of 1ml once a day. If slight adverse reaction occurs when using the medicine, 0.5ml twice a day can be used after consulting with a specialized doctor. It is recommended that patients use the medication in strict accordance with the doctor’s instructions for safe use of medication, patients should not blindly use cetirizine hydrochloride drops without authorization, need to be under the guidance of a specialist.