THE DOSE AND DURATION OF EFFECT OF LEVOCABASTINE, A NEW TOPICAL H-1 ANTAGONIST, ON NASAL PROVOCATION REACTION TO ALLERGEN

This study investigated the dose and duration of effect of topical lev ocabastine (LC) in patients with perennial allergic rhinitis as evalua ted by the effect on nasal provocation test with house dust antigen. T hree different doses (0. 05, 0. 1, and 0.2 mg) of LC were independentl y administered to evaluate the dose response and duration of effect. R eaction to nasal provocation was evaluated by a scoring system based o n a combination of symptoms, such as number of sneezes, degree of nasa l discharge, and nasal obstruction. The mean scores at 30 minutes post administration of each of the three different doses of LC showed a sig nificant decrease as compared with those of preadministration. The eff ect persisted for 4 hours with a dose of 0.05 mg and 0.1 mg of LC and for 12 hours with 0. 2 mg of LC In a comparison of the three doses pot ency of effect of LC, the highest dose (0.2 mg) demonstrated the stron gest effect in the interval from 4 hours to 10 hours postadministratio n. These results indicate that LC has an immediate effect and its effe ct is dose dependent. The present study suggests that nasal symptoms i n perennial allergic rhinitis could be relieved by topical application of 0.2 mg of LC, twice a day.