Efficacy of desloratadine in intermittent allergic rhinitis: a GA2LEN study

Background:  The Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines proposed a classification for allergic rhinitis based on the duration of symptoms (intermittent, persistent) rather than on the time of allergen exposure (seasonal, perennial). There is no placebo-controlled, randomized clinical trial on intermittent allergic rhinitis (IAR) to date. Desloratadine (DL) is recommended for the first-line treatment of seasonal and perennial allergic rhinitis. Objectives:  To assess the efficacy and safety of DL in subjects with IAR based on the ARIA classification. Methods:  Patients over 12 years of age with IAR were assessed over 15 days of treatment with DL 5 mg once daily (n = 276) or placebo (n = 271). The primary endpoint was the AM/PM reflective total 5 symptom score (T5SS). Secondary endpoints included AM/PM instantaneous T5SS and individual symptoms, therapeutic response, symptom severity by visual analogue scale, and quality-of-life. Results:  The mean reduction of AM/PM reflective T5SS was significantly greater with DL than with placebo over 15 days (−3.01 vs−2.13, P < 0.001) and on each individual day (P < 0.05). Mean AM instantaneous T5SS was reduced significantly with DL compared to placebo as early as day 2 (−1.84 vs−0.89; P < 0.001). The therapeutic response and improvement in quality-of-life were significantly greater with DL than with placebo (P < 0.001 for each). The frequency of treatment-related adverse events was low and similar between DL (7.2%) and placebo (7.0%). Conclusions:  This is the first large trial to show that treatment can be effective in IAR. Desloratadine was effective and safe.