Reference

Comparative antiallergic effects of second-generation H1-antihistamines ebastine, cetirizine and loratadine in preclinical models

Comparative antiallergic effects of second-generation H1-antihistamines ebastine, cetirizine and loratadine in preclinical models. Llupia, Josep; Gras, Jordi; Llenas, Jesus (Research Center, Almirall Prodesfarma, Barcelona, Spain). Arzneimittel-Forschung, 53(2), 93-97 (English) 2003 Editio Cantor Verlag. CODEN: ARZNAD. ISSN: 0004-4172. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Ebastine (CAS 90729-43-4), cetirizine (CAS 83881-51-0) and loratadine (CAS 79794-75-5) are second generation H1-antihistamines of proven efficacy for treating allergy. Recent clin. studies have found ebastine to be more effective than cetirizine or loratadine in alleviating the symptoms of seasonal allergic rhinitis. The objective of this study was to compare the efficacy of these compds. in three guinea-pig models of bronchoconstriction, elicited either by histamine, allergen or leukotriene C4 in order to shed light onto the mechanisms that might explain differences found in clin. studies. In the present expts., ebastine and cetirizine were equipotent against aerosol histamine-induced bronchospasm in guinea pigs (ED50 115 and 100 mg/kg p.o., resp.), while loratadine was three-fold less potent. In the same model the effects of ebastine, loratadine and cetirizine lasted 21, 19 and 15 h, resp. Ebastine (ED50 334 mg/kg p.o.) was the most potent compd. in inhibiting allergen-induced bronchospasm in conscious guinea pigs. In vitro studies in tracheally perfused guinea pig lungs demonstrated that ebastine and loratadine inhibited with equal potency the bronchoconstriction induced by leukotriene C4 while cetirizine was significantly less potent. Finally, in another in vivo study, ebastine reverted the changes in pulmonary resistance induced by leukotriene C4 in anesthetized guinea pigs, whereas cetirizine and loratadine were devoid of activity in this model. In accordance with the clin. data, ebastine proved to be the substance with the widest range of application in animal expts., too.

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

Clinical study of the therapeutic efficacy and safety of emedastine difumarate versus cetirizine in the treatment of seasonal allergic rhinitis. Horak, Friedrich; Stuebner, Petra; Zieglmayer, Rene; Kavina, Alexander; Corrado, Mario E.; Assandri, Alessandro; Mion, Alberto ( Ear-Nose-Throat University Clinic, Vienna, Austria). Arzneimittel Forschung, 54(10), 666-672 (English) 2004 Editio Cantor Verlag. CODEN: ARZNAD. ISSN: 0004-4172. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) 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. The study was designed as a double-blind, randomized, parallel groups comparison of two antihistamines administered by oral route (emedastine 4 mg o.d. vs. 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 lab. assays and recording vital signs and adverse events (AEs). The between-group difference in primary efficacy variable averaged over the 2-wk 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 compds. 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. 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.