Treatment of seasonal allergic rhinitis in children with cetirizine or chlorpheniramine: A multicenter study

Cetirizine, a selective H-1-antagonist, has been found efficacious in the treatment of seasonal allergic rhinitis (SAR) when given once daily. In the present multicenter, randomized, parallel-group study the efficacy and safety of cetirizine (5-10 mg in a single dose or 2 divided doses) and of an active control, chlorpheniramine (2 mg tid), were compared in children aged 6-11 years with SAR at 4 centers. Patients rated symptoms twice daily on diary cards on a 4-point scale, for sneezing, nasal discharge, itchy eyes, itchy nose or mouth, conjunctivitis, and nasal congestion. A total symptom severity (TSS) score was derived from all symptoms except nasal congestion. TSS score at entry was 5.8 for each treatment group and was markedly reduced after 2 weeks' treatment: cetirizine once daily, -2.5; cetirizine twice daily, -2.6; chlorpheniramine -2.6; there were no statistically significant differences between groups (p = 0.91). Individual symptoms and investigator ratings followed this pattern. Reduction in TSS occurred after the first dose within the first 12 h [-1.6, -2.1, and -1.2, respectively (p < 0.03)] confirming a rapid onset of action. There was no exacerbation of asthma among the 117 patients entering with mild-to-moderate asthma. Most of the patients who experienced adverse events reported only mild-to-moderate severity. Cetirizine, given once daily or in divided doses twice daily and chlorpheniramine given 3 times daily for SAR in children aged 6-11 years, had a rapid onset of action. Neither drug was associated with worsening of asthma.