Abstract
Purpose: :
To evaluate the efficacy of the oral antihistamine desloratadine 5mg versus placebo in preventing ocular allergic signs and symptoms as induced by the conjunctival allergen challenge (CAC) model in subjects with a history of seasonal allergic rhinoconjunctivitis.
Methods: :
This was a double–masked, placebo–controlled, crossover, single–center, 6–visit study. Allergen response was determined at Visit 1 and confirmed at Visit 2. Forty–one subjects were randomized at Visit 3 to receive either the placebo–desloratadine treatment sequence or desloratadine–placebo treatment sequence. The first dose of study medication for Phase A (either desloratadine or placebo) was administered and subjects were instructed to continue once–daily dosing for at least 5 days. At Visit 4, 3 hours following the seventh study medication dosing for Phase A, CAC was administered and signs and symptoms were assessed (ocular itching evaluated at 3, 5, & 7 min post–CAC; ocular redness, chemosis, lid swelling, and tearing evaluated at 10, 15 and 20 minutes post–CAC). At Visit 5, following a two–week washout period, subjects were crossed over and were administered the first dose of study medication for treatment Phase B. At Visit 6, following at least 5 days of once–daily dosing, subjects were administered the seventh dose of study medication for treatment Phase B. CAC administration and sign/symptom assessment were carried out as with Phase A.
Results: :
Desloratadine treatment was statistically significantly more effective than placebo in the prevention of: ocular itching at 3, 5, and 7 minutes post–CAC (p<0.001); ciliary redness at 10 minutes post–CAC (p=0.048); episcleral redness at 10 minutes post–CAC (p=0.045); chemosis at 10 (p=0.020), 15 (p=0.026), and 20 (p=0.003) minutes post–CAC; lid swelling at 10 (p=0.002), 15 (p=0.026), and 20 (p=0.004) minutes post–CAC; and tearing at 10 (p=0.003), 15 (p=<.001), and 20 (p=0.001) minutes post–CAC.
Conclusions: :
Overall, desloratadine was a safe treatment, resulting in significant effects to prevent the signs and symptoms of allergic conjunctivitis.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • inflammation