Evaluation of desloratadine on conjunctival allergen challenge-induced ocular symptoms.

BACKGROUND: Allergic conjunctivitis (AC) is frequently associated with allergic rhinitis (AR) and affects up to 91% of patients with AR. Desloratadine, an orally administered, non-sedating second-generation antihistamine, has proven efficacy and safety in the control of nasal and non-nasal--including ocular--symptoms of AR. This randomized-controlled trial is the first to evaluate the effects of continuous oral desloratadine treatment on ocular symptoms after conjunctival allergen challenge.

OBJECTIVE: To evaluate the impact of administering oral desloratadine 5 mg daily for 7 days on ocular symptoms in conjunctival allergen-challenged subjects.

METHODS: In this crossover study, adults with a history of seasonal AC and a minimal threshold response to allergen challenge were randomized to receive desloratadine 5 mg daily (n=20) or placebo (n=21) for 7 days after which they underwent a second ocular allergen challenge. After a 2-week washout period, subjects crossed over to the other treatment. The primary efficacy parameter was the intra-subject difference from baseline at end-point in the post-challenge mean composite ocular redness score (the sum of redness scores in ciliary, conjunctival, or episcleral vessel beds). Secondary efficacy parameters included the intra-subject and inter-subject differences in individual symptom scores for ciliary, conjunctival, or episcleral redness; pruritus; chemosis; eyelid swelling; and tearing.

RESULTS: The mean composite ocular redness score was reduced at 10, 15, and 20 min post-challenge with desloratadine treatment compared with placebo, though these differences were not statistically significant (P=NS). Desloratadine was significantly more effective than placebo in preventing post-challenge ocular pruritus (P<0.001). Significant improvements post-challenge were also seen in ciliary and episcleral redness, chemosis, eyelid swelling, and tearing (P<0.05 vs. placebo for all comparisons). Desloratadine was well tolerated.

CONCLUSION: Treatment with desloratadine 5 mg daily for 7 days reduced allergic ocular symptoms following allergen challenge.