Clinical efficacy of olopatadine hydrochloride ophthalmic solution 0.2% compared with placebo in patients with allergic conjunctivitis or rhinoconjunctivitis: a randomized, double-masked environmental study.

BACKGROUND: Previous studies have suggested that olopatadine hydrochloride ophthalmic solution 0.2% administered once daily is effective for up to 24 hours after instillation and is well tolerated in adults and children aged > or =3 years.

OBJECTIVE: The goal of this study was to evaluate the efficacy and safety profile of olopatadine 0.2% compared with placebo in patients with seasonal allergic conjunctivitis or rhinoconjunctivitis.

METHODS: This was a 10-week, randomized, placebo-controlled, double-masked environmental study conducted during the spring allergy season (April-August) of 2003. Patients assessed their ocular signs and symptoms in terms of frequency (whole-unit scale from 0 to 5) and severity (half-unit scale from 0 to 4), and grass pollen counts were obtained daily for each investigative site. Responder analyses were conducted by pollen level (frequency based) and pollen period (severity based) to evaluate the clinical significance of differences in ocular itching and redness between treatment groups.

RESULTS: Two hundred sixty patients (137 females, 123 males) were enrolled in the study, including 28 children aged between 11 and 17 years; the overall population was 74% white, 11% black, 4% Hispanic, and 11% other. The frequency-based responder analyses of ocular itching and redness showed that when grass pollen counts were high (>20 gr/m(3) air), a respective 21% and 14% of patients in the olopatadine 0.2% group assessed the frequency of ocular itching and redness as >2, compared with 47% and 31% of patients in the placebo group (P < 0.001 for ocular itching; P < 0.003 for redness). The results of the severity-based responder analyses by peak pollen period were consistent with those of the frequency-based analyses. Compared with placebo, olopatadine 0.2% was associated with significant reductions in calculated mean scores for ocular itching and redness by pollen level and by pollen period. No patient was discontinued from the study because of a treatment-related adverse event, and no patient experienced a treatment-related serious adverse event.

CONCLUSION: In the patients studied, olopatadine 0.2% appeared to be effective and well tolerated when administered once daily for the treatment of the ocular signs and symptoms of allergic conjunctivitis or rhinoconjunctivitis.