Zyrtec is a selective antagonist with a histamine H1 receptor devoid of any significant anticholinergic and antiserotonin effects.

Cetirizine reduces eosinophyles migration and inhibits excretion of mediators, decrease bronchial hyperreactivity, it does not pass hematoencephalic barrier. Cetirizine is not metabolized in liver. In therapeutic doses it provokes drowsiness and abirritation.

Zyrtec is contraindicated in patients with a known hypersensitivity to any of its ingredients or to hydroxyzine. Do not take Zyrtec without first talking to your doctor if you are pregnant.

Zyrtec is used for the relief of symptoms associated with seasonal allergic rhinitis, perennial allergic rhinitis and chronic idiopathic urticaria. Zyrtec reduces also pruritus and Quincke edema.

Adults and children over12 years old and elder – the dose is 10 milligrams once daily. The recommended dose of Zyrtec in children aged 2-6 years old is 5mg once daily or 5 drops twice a day in the morning and in the evening.

In children aged 6-12 years old the recommended dose of Zyrtec is 10mg (1 tablet or 20 drops) once a day or ½ tablet (10 drops) twice a day (in the morning and in the evening). Patients with impaired renal or hepatic function should use the lower recommended dose of Zyrtec.

Any medication taken in excess can have serious consequences. In adults, the primary symptom of a Zyrtec overdose is extreme sleepiness. In severe intoxication it is better to follow these methods: to take activated charcoal or gastric lavage.

Because cetirizine is excreted in milk, use of Zyrtec in nursing mothers is not recommended. Caution should therefore be exercised when driving a car or operating potentially dangerous machinery after taking Zyrtec. Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking Zyrtec.

Most side effects reported during therapy with Zyrtec (Cetirizine) were drowsiness, dizziness, dry mouth, headache, gastro-intestinal disturbance. Rare side effects like allergic reactions.