Desloratadine therapy for symptoms associated with perennial allergic rhinitis

Perennial allergic rhinitis (PAR) has a substantial negative social and economic impact. Recent studies emphasize the potential seriousness of PAR and the need for improved treatment of this condition.

To confirm the efficacy and safety of the H1-antihistamine desloratadine in reducing the symptoms of PAR in a randomized, double-blind, placebo-controlled trial.

Patients with PAR (N = 1,179) from 67 US/international centers received desloratadine, 5 mg once daily, or identical placebo tablets. The primary efficacy measure was the change from baseline to week 4 in average morning and evening reflective total symptom scores (TSSs). Secondary end points included changes from baseline in total nasal and nonnasal symptom scores and peak nasal inspiratory flow (PNIF) rates.

Desloratadine was significantly more effective than placebo in reducing morning and evening reflective TSSs for each week and during weeks 1 through 4 (P = .001). Mean changes in TSSs during the 4-week study were -3.9 (26.6% reduction) and -3.2 (22.3% reduction) for the desloratadine and placebo groups, respectively (P = .001, desloratadine vs placebo). With desloratadine therapy, significant improvements were also seen in secondary efficacy end points compared with placebo use (total nasal and nonnasal symptom scores: P < or = .04). Improvements in mean morning PNIF were significantly greater in the desloratadine-treated group than in the placebo group (P = .03).

These results confirm and extend previous findings that desloratadine is safe and is associated with a statistically significant reduction in nasal and nonnasal symptoms in patients with PAR. Objective nasal airflow, evaluated by PNIF, was statistically significantly improved after desloratadine treatment.