The effect of a combined therapy with a histamine H1 antagonist and a chemical mediator release inhibitor on allergic conjunctivitis.

To evaluate the efficacy of a combined therapy with levocabastine hydrochloride ophthalmic suspension and pemirolast potassium ophthalmic solution compared to single therapy with levocabastine hydrochloride ophthalmic suspension alone. Thirty-two allergic conjunctivitis patients were randomized to combined-treatment (n = 15) or single-treatment groups (n = 17). The improvement of subjective symptoms as well as objective findings were evaluated. The degree of improvement was significantly higher in the combined-treatment group for lacrimation (p = 0.008) among the subjective symptoms, for conjunctival edema (p = 0.030), eyelid edema (p = 0.032) and conjunctival papilla formation(p = 0.040) among the objective findings. Both objective assessments and subjective symptoms of allergic conjunctivitis showed the greatest improvements when patients were treated with combined therapy as compared to single-agent therapy. The enhanced benefits of combined therapy may result from these agents having different mechanisms of action.