Emedastine ophthalmic solution 0.05% versus levocabastine ophthalmic suspension 0.05% in the treatment of allergic conjunctivitis using the conjunctival allergen challenge model

PURPOSE: To compare a new ocular antihistamine, emedastine difumarate (Emad ine Ophthalmic Solution 0.05%; Alcon Laboratories, Fort Worth, Texas), with the marketed ocular antihistamine, levocabastine hydrochloride (Livostin O phthalmic Suspension 0.05%; CIBA Vision, Atlanta, Georgia), in the treatmen t of allergic conjunctivitis after conjunctival allergen challenge. METHODS: We performed a prospective, double-masked, randomized, contralater al eye study comparing emedastine 0.05% in one eye with levocabastine 0.05% or emedastine vehicle (placebo) in the contralateral eye. Efficacy was det ermined 10 minutes and 2 hours after administration of study medications. O cular itching and redness scores were recorded 3, 5, and 10 minutes after c onjunctival allergen challenge. RESULTS: A total of 97 subjects with a history of allergic conjunctivitis a nd a positive response to a diagnostic test were evaluable for safety analy sis, and 91 subjects were evaluable for the efficacy analysis. Emadastine 0 .05% was statistically significantly more effective than levocabastine 0.05 % in reducing ocular itching after conjunctival allergen challenge in both the 10-minute and the 2-hour challenge (P < .05), Emedastine 0.05% and levo cabastine 0.05% were statistically equivalent in reducing conjunctival redn ess after conjunctival allergen challenge, although emedastine tended to be more efficacious than levocabastine at every observation time point. CONCLUSIONS: After conjunctival allergen challenge, emadastine 0.05% is sig nificantly more effective than levocabastine 0.05% in reducing ocular itchi ng associated with allergic conjunctivitis. The two compounds are equivalen t in controlling the conjunctival redness associated with allergic conjunct ivitis. (C) 2000 by Elsevier Science Inc. All rights reserved.