Rapid onset of action of levocabastine eye-drops in histamine-induced conjunctivitis.

Levocabastine is a recently developed, potent H1-receptor blocker intended for topical application. Seventeen healthy non-atopic volunteers participated in this randomized, double-blind, placebo-controlled study undertaken to investigate the speed of onset of action, efficacy and tolerability of levocabastine eye-drops after a histamine challenge. The degree of histamine-induced ocular inflammation was found to be significantly less after administration of levocabastine compared with placebo. Furthermore, levocabastine was shown to be rapidly effective with an onset of action within 10 min. Levocabastine eye-drops were well-tolerated and no adverse reactions to the study drug were reported. Levocabastine eye-drops appear to be a valuable therapeutic approach for the treatment of histamine-mediated ocular allergies.