Clinical study of the therapeutic efficacy and safety of emedastine difumarate versus cetirizine in the treatment of seasonal allergic rhinitis.

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.

Onset and duration of action of ketotifen 0.025% and emedastine 0.05% in seasonal allergic conjunctivitis : efficacy after repeated pollen challenges in the vienna challenge chamber.

OBJECTIVE: To compare the efficacy, onset and duration of action, and the safety of ketotifen fumarate 0.025% ophthalmic solution and emedastine difumarate 0.05% ophthalmic solution in subjects with seasonal allergic conjunctivitis (SAC) induced by allergen exposure, using the Vienna Challenge Chamber model. DESIGN AND SETTING: This was a double-masked, randomised, comparative, crossover study conducted at an allergy outpatient clinic in Austria. STUDY PARTICIPANTS: Subjects with an allergy to grass pollen were exposed to the allergen in a pollen chamber for 4 hours, followed by a 3-hour break and then a second exposure for 3 hours. INTERVENTIONS: Study participants were randomised to a treatment sequence (ketotifen followed by emedastine or emedastine followed by ketotifen), receiving 1 drop per eye of ketotifen or emedastine 2 hours after the initial allergen exposure in the pollen chamber. OUTCOMES: Individual and composite ocular, individual and composite nasal, and total (ocular + nasal) symptom complex scores were determined by repeated exposure to allergen 0-2 hours and 5-8 hours after dosing. Onset of action was defined as the time to the first observation of a 20% reduction from baseline in the composite ocular symptom score. RESULTS: All 37 subjects enrolled completed the study. The median time to onset of action was 15 minutes for ketotifen and 30 minutes for emedastine. This difference was significant using the generalised linear model (p = 0.048), but not for the log-rank test analysis. In the initial 2 hours post dose, ketotifen provided significantly greater relief of both composite ocular symptoms (p = 0.026) and total symptom complex (p = 0.014). Both medications were effective in reducing symptoms 5 to 8 hours after dosing. No adverse events were reported for either treatment. CONCLUSIONS: In the Vienna Challenge Chamber model, ketotifen and emedastine both effectively alleviated ocular symptoms of SAC after single-dose administration. Ketotifen had a faster onset of action and provided better symptom relief than emedastine during the first 2 hours after dosing. The rapid onset of action and symptom control make ketotifen a valuable treatment for SAC.