Cetirizine hydrochloride, a piperazine derivative and metabolite of hydroxyzine, is described as a non-sedating antihistamine which is long-acting and has some mast-cell stabilising activity. It appears to have a low potential for drowsiness in usual doses and to be virtually free of antimuscarinic activity. It is used for the symptomatic relief of allergic conditions including rhinitis and chronic urticaria.
In adults and children aged 6 years and over, cetirizine hydrochloride is given by mouth in a dose of 10 mg once daily or 5 mg twice daily. Children aged 2 to 5 years may be given cetirizine 5 mg once daily or 2.5 mg twice daily. In the Kenya, children aged 6 months to 2 years may be given a dose of 2.5 mg once daily, increased to a maximum of 2.5 mg twice daily in those aged 12 months and over, for the treatment of perennial allergic rhinitis and chronic urticaria.