Efficacy of loratadine-montelukast on nasal congestion in patients with seasonal allergic rhinitis in an environmental exposure unit

Abstract

Nasal congestion is considered to be one of the most bothersome symptoms of allergic rhinitis (AR) and often the most difficult to treat. Oral therapies providing safe, effective, and reliable relief of AR symptoms, including nasal congestion, are limited. To evaluate the efficacy of a single dose of loratadine-montelukast (10 mg/10 mg) vs placebo and phenylephrine (10 mg) in relieving nasal congestion over 6 hours after ragweed pollen exposure in the environmental exposure unit at the Kingston General Hospital. After a screening visit and up to 6 priming visits, patients who met minimum symptom requirements during ragweed pollen exposure were randomized to receive loratadine-montelukast, phenylephrine, or placebo. Patients evaluated nasal congestion and other symptoms of AR and measured peak nasal inspiratory flow before dosing and at 20-minute intervals during the subsequent 8 hours of pollen exposure. During the first 6 hours after treatment (primary end point), loratadine-montelukast treatment resulted in greater improvement in the mean nasal congestion score vs placebo (P = .007) and phenylephrine (P < .001). Loratadine-montelukast was more effective than placebo (P < or = .02) and phenylephrine (P < or = .002) in relieving total symptoms, nasal symptoms, and nonnasal symptoms and in improving peak nasal inspiratory flow. There were no statistically significant differences between phenylephrine and placebo for any measures. Fewer patients in the loratadine-montelukast group (3.9%) reported adverse events than in the phenylephrine (7.9%) and placebo (7.1%) groups; most adverse events were mild or moderate. Loratadine-montelukast was more effective than placebo and phenylephrine in relieving nasal congestion and other nasal and nonnasal symptoms resulting from ragweed pollen exposure. There was no statistically significant difference between phenylephrine and placebo.