The Second-Generation (Peripherally-Selective) Antihistamines in Children

Marcia L. Buck, Pharm.D., FCCP


Pediatr Pharm. 2001;7(4) 

In This Article

Recent Clinical Trials

The safety and efficacy of the second generation antihistamines are well established in adolescents and adults.[2,4] Although there are differences in potency as measured by their ability to suppress a histamine-induced wheal and flare response (cetirizine > fexofenadine > loratadine), there appears to be relatively little difference in patient response at equivalent doses.[5,6]

Several studies have become available in recent years that describe the efficacy of the second generation antihistamines in younger children. In 1999, Sienra-Monge and colleagues published the results of a trial comparing cetirizine and loratadine in children ages 2-6 years.[7] Eighty children with known allergies were randomized in this prospective, double-blind, longitudinal study. The children received a dose of 0.2 mg/kg of either drug for a period of 28 days. As anticipated, cetirizine produced a significantly greater inhibition of the wheal response compared with loratadine. Eosinophil counts and global evaluations by the investigators were not different between the groups. Both drugs produced significant improvement in symptoms, according to the parents' diaries, but cetirizine appeared to cause a greater reduction in rhinorrhea, sneezing, nasal obstruction, and nasal pruritis. The authors concluded that both drugs were well tolerated and effective, with a greater response seen from cetirizine.

Over the past several years, results from the Early Treatment of the Atopic Child (ETAC) program have provided clinicians with a great deal of information about antihistamines in toddlers.[8,9] These investigators hypothesized that early intervention with an antihistamine would be safe in atopic young children and would prevent or delay the onset of asthma. A total of 817 European children with atopic dermatitis at 1 to 2 years of age were randomized to receive 0.25 mg/kg cetirizine twice daily or placebo. While the overall analysis failed to reach statistical significance, in the subset of children sensitized to pollen or dust mites, there was a 50% reduction in the development of asthma symptoms compared to the placebo group.[8]

The safety evaluation conducted during the ETAC trial was published separately.[9] A total of 399 children receiving cetirizine and 396 receiving placebo were evaluated over a period of 18 months. Compared with placebo, the cetirizine-treated toddlers had no clinically relevant differences in neurologic or cardiovascular symptoms, growth, behavior, developmental assessments, or laboratory tests. The overall rate of adverse effects was 2.3% in the cetirizine group versus 2.0% for placebo.


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