Zyrtec 1mg/ml Oral Solution 75mlZyrtec Oral Solution contains Cetirizine which is an antihistamine used to relieve allergy symptoms such as watery eyes, runny nose, itching eyes nose, sneezing, hives, and itching. It works by blocking a certain natural substance (histamine) that your body makes during an allergic reaction. Dose Shake well before use. Zyrtec Syrup may be taken with or without food, but it is better to take it at a fixed time. Adults and children 6 years and older: 5