Clinical Study of the Therapeutic Efficacy and Safety of Emedastine Difumarate versus Cetirizine in the Treatment of Seasonal Allergic Rhinitis

Summary Objective: The therapeutic efficacy and tolerability of emedastine difumarate (CAS 87233-62-3) in male and female Caucasian patients with seasonal allergic rhinitis as compared to cetirizine (CAS 83881-51-0) was evaluated. Methods: The study was designed as a double-blind, randomised, parallel groups comparison of two antihistamines administered by oral route (emedastine 4 mg o.d. versus cetirizine 10 mg o.d.) in a population of 120 patients suffering from grass pollen allergic rhinitis. The duration of the treatment period was 14 days. Primary efficacy variable was a total symptoms score (including among symptoms nasal congestion, sneezing, rhinorrhea, nasal/throat/palate itching, eye itching and lacrimation) evaluated after 14 days of treatment vs. baseline value. Safety was assessed on routine laboratory assays and recording vital signs and adverse events (AEs). Results: The between-group difference in primary efficacy variable averaged over the 2-week treatment period was not statistically significant. Results clearly showed that no significant difference exists between the two treatments as far as total symptoms score evaluated after 14 days of treatment vs. baseline values are concerned. Therefore, the efficacy profiles of the study medications are overlapping. The pattern and incidence of AEs was similar in both treatment groups. The most frequent AEs with both compounds were related to the CNS, headache being the most reported one. In particular, this study seems to disclose a slighter tendency to drowsiness with emedastine than with cetirizine. Conclusions: Both drugs under investigation in this trial appear to be effective for relieving the symptoms of seasonal allergic rhinitis in Caucasian adult patients. The results demonstrate that emedastine 4 mg o.d. is comparable in efficacy to cetirizine 10 mg once daily in the symptomatic management of seasonal allergic rhinitis. Moreover, based on the results of this study, emedastine can be considered a safe and well-tolerated drug and its safety profile seems to resemble that of cetirizine.