Comparison of ketotifen fumarate ophthalmic solution alone, desloratadine alone, and their combination for inhibition of the signs and symptoms of seasonal allergic rhinoconjunctivitis in the conjunctival allergen challenge model: a double-masked, placebo- and active-controlled trial

Abstract

Background: Ketotifen fumarate is a topical antiallergic combination mast-cell stabilizer and antihistamine indicated for the temporary prevention of ocular itching due to allergic conjunctivitis. Desloratadine is a systemic antihistamine indicated for the treatment of seasonal and perennial allergic rhinitis.

Objective: The purpose of this study was to compare the efficacy of ketotifen 0.025% ophthalmic solution instilled in the eye, desloratadine 5-mg tablets taken orally, and their combination for prevention of the signs and symptoms of allergic rhinoconjunctivitis, as induced by the conjunctival allergen challenge (CAC) model.

Methods: This was a randomized, double-masked, placebo- and active-controlled, single-center clinical trial. At visit l, the dose of allergen necessary to elicit a qualifying allergic reaction was determined for subjects meeting the entry criteria. At visit 2, the allergen dose determined at visit 1 was confirmed, and all subjects who had a qualifying ocular and nasal allergic reaction were randomized to 1 of 3 treatment groups: ketotifen ophthalmic solution and placebo tablet, desloratadine tablet and placebo eyedrop, or ketotifen and desloratadine. Subjects were instructed to instill 1 drop into each eye twice daily and take 1 tablet with water once daily at the same time as the morning eyedrop for approximately 4 weeks. At visit 3, subjects brought in their medication and were given 1 drop of the eyedrop bilaterally and 1 tablet with water. Bilateral CAC was performed 2 hours after administration of medication. Using standardized scales, subjects rated ocular itching at 3, 5, and 7 minutes after CAC; ocular tearing and eyelid swelling at 10, 15, and 20 minutes after CAC; and nasal signs and symptoms (sneezing, rhinorrhea and postnasal drip, pruritus, and nasal congestion) at 10, 20, 30, 40, and 50 minutes after CAC. The investigator graded ocular redness and chemosis at 10, 15, and 20 minutes after CAC. At all visits, subjects were offered an anti-allergy eyedrop to relieve any immediate ocular discomfort caused by CAC.

Results: One hundred two subjects were screened-82 (55 women, 27 men; mean age, 42.8 years [range, 21-70 years]) were randomized to treatment, and 80 completed the study. Subjects in the group that received ketotifen (n = 27) and the group that received ketotifen with desloratadine (n = 26) had significantly lower mean itching scores compared with those in the group that received desloratadine alone (n = 27) at all time points (P </= 0.05). Total ocular redness, calculated by summing the mean redness scores for each of the 3 vessel beds, was significantly lower in the ketotifen group than in the other treatment groups at most time points (P </= 0.05). All treatments attenuated nasal symptoms; no statistically significant differences were noted between treatment groups, with the exception of the 50-minute time point, at which combination treatment was significantly more effective than ketotifen alone (P </= 0.05). The proportion of subjects who requested relief drops after CAC was significantly lower in both the ketotifen alone and combination treatment groups compared with the desloratadine alone group (P = 0.004).

Conclusions: Ketotifen ophthalmic solution significantly decreased the signs and symptoms of ocular and nasal allergic rhinoconjunctivitis. The addition of ketotifen to the oral desloratadine regimen improved the overall antiallergic efficacy of both medications.