Efficacy and safety of rupatadine in Japanese patients with seasonal allergic rhinitis: A double-blind, randomized, multicenter, placebo-controlled clinical trial.

Background: Rupatadine is a novel non-sedating second-generation H-antihistamine with antiplatelet-activating factor activity, first marketed in Spain in 2003. It is used for treating allergic rhinitis in more than 80 countries. This study investigated its efficacy and safety in Japanese patients with seasonal allergic rhinitis (SAR).

Methods: This was a randomized, placebo-controlled, double-blind study conducted at 4 medical institutions in Japan (JapicCTI-152785). Adolescent and adult SAR outpatients aged 12-64 years entered a 1-week placebo run-in period. After eligibility was confirmed, patients orally received placebo, rupatadine 10 mg, or 20 mg once daily for 2 weeks. The primary endpoint was a change from baseline to second week of treatment in total 4 nasal symptom score (T4NSS).

Results: Nine hundred patients were randomly assigned to placebo, rupatadine 10 mg, or rupatadine 20 mg (302, 298, and 300 patients, respectively). The least squares mean difference in the primary endpoint between rupatadine and placebo was -1.085 for 10 mg, and -1.415 for 20 mg (analysis of covariance, both P < 0.001). The rates of adverse events were 6.6%, 14.1%, and 15.0% for placebo, rupatadine 10 mg, and rupatadine 20 mg, respectively. Somnolence was most frequently reported: 7.0% for rupatadine 10 mg and 7.3% for rupatadine 20 mg. No serious adverse drug reactions were observed, and no adverse events resulted in premature discontinuation.

Conclusions: Rupatadine 10 and 20 mg were significantly superior to placebo in improving nasal and ocular symptoms of SAR, and were well tolerated.