Inhibitory effect of levocabastine on experimental allergic conjunctivitis in guinea pigs

The effect of levocabastine on allergic and histamine (Hi)-induced conjunctivitis in guinea pigs was compared with those of cromolyn sodium and amlexanox. Levocabastine inhibited both antigen- and Hi-induced conjunctivitis. Amlexanox had no effect on Hi-induced conjunctivitis; however, the drug elicited a significant inhibition of allergic conjunctivitis. On the other hand, the effect of cromolyn sodium was almost negligible in both cases. Levocabastine moderately inhibited Hi release from guinea pig conjunctiva induced by antigen-antibody reactions. Amlexanox also caused a significant inhibitory effect, whereas cromolyn sodium was not effective in suppressing Hi release induced by antigen challenge. Furthermore, levocabastine prevented an increase in the vascular permeability elicited by both Hi and antigen instillation.