Safety of cetirizine in infants 6 to 11 months of age: A randomized, double-blind, placebo-controlled study

Background: H1-antihistamines are widely used for symptom relief in allergic disorders in infants and children; however, there are few prospective, randomized, double-blind, controlled studies of these medications in young children, and to date, no such studies have been conducted in infants. Objective: This prospective, randomized, parallel-group, double-blind, placebo-controlled study was designed to evaluate the safety of the H1-antihistamine cetirizine, particularly with regard to central nervous system and cardiac effects, in infants age 6 to 11 months, inclusive. Methods: Infants who met the entry criteria for age and had a history of treatment with an H1-antihistamine for an allergic or other disorder were randomized to receive 0.25 mg/kg cetirizine orally or matching placebo twice daily orally for 1 week. Results: The mean daily dose in cetirizine-treated infants was 4.5 ± 0.7 mg (SD). No differences in all-cause or treatment-related adverse events were observed between the cetirizine- and placebo-treated groups. A trend was observed toward fewer adverse events and sleep-related disturbances in the cetirizine group compared with the placebo group. No prolongation in the linear corrected QT interval was observed in cetirizine-treated infants compared with either baseline values or with values in placebo-treated infants. Conclusions: We have documented the safety of cetirizine in this short-term investigation, the first randomized, double-blind, placebo-controlled study of any H1-antihistamine in infants. Additional prospective, randomized, double-blind, placebo-controlled, long-term studies of cetirizine and other H1-antihistamines are needed in this population. (J Allergy Clin Immunol 2003;111:1244-8.)