Effect of loteprednol etabonate nasal spray suspension on seasonal allergic rhinitis assessed by allergen challenge in an environmental exposure unit.

Background: Loteprednol etabonate (LE) is a novel soft steroid that was designed to improve the benefit/risk ratio of topical corticosteroid therapy. This study assesses the clinical efficacy and safety of three different doses of LE nasal spray in seasonal allergic rhinitis (SAR). Methods: In this single-center, double-blind, placebo-controlled, parallel-group trial 165 subjects with SAR to grass pollen received daily single doses of either 100, 200, 400 mug LE nasal spray, or placebo for 14 days. The patients underwent three 4-h allergen challenges with grass pollen in an environmental exposure unit at a screening visit (baseline) and on days 7 and 14 of treatment. Standardized nasal symptom scores were obtained every 20 min. Nasal flow, nasal secretions, and FEV1 were measured every hour during allergen challenges. Results: After 14 days of treatment, patients who received 400 mug LE had significantly lower total nasal symptom scores compared with those receiving placebo (P = 0.007). LE400 reduced rhinorrhea, nasal congestion, nasal itching, the amount of nasal secretions, and improved nasal flow as compared with placebo (P < 0.05). LE100 and LE200 were not significantly different from placebo. All treatments were well tolerated. Conclusions: Loteprednol 400 mug once daily is superior to placebo and the only effective dose tested in improving nasal symptoms and objective parameters in patients with SAR.