Onset of action of mometasone furoate nasal spray (NASONEX (R)) in seasonal allergic rhinitis

Background: Mometasone furoate nasal spray (MFNS, MASONEX(R)), is a new syn thetic corticosteroid with considerable efficacy in the treatment of season al and perennial rhinitis and less than 0.1% systemic absorption. This stud y was designed to evaluate the time of onset of action of MFNS. The subject s were evaluated over the course of 2 weeks during the spring allergy seaso n. Methods: The effects of MFNS 200 mu g given once daily for 2 weeks were eva luated in a randomized, multicenter, double-blind, placebo-controlled study in 201 patients with seasonal allergic rhinitis. Clinically significant on set of action was assessed prospectively by special patient diary cards kep t during the first 3 days of treatment. Results: By 12 h after initial dosage (the earliest evaluation), 28% of pat ients in the MFNS group experienced clinically significant relief, compared with 13% of those given placebo (P=0.01). Median time to at least moderate symptom relief in patients who received MFNS was 35.9 h, compared with mor e than 72 h in patients given placebo (P<0.01). By 72 h, 64% of the patient s receiving MFNS experienced at least moderate relief, compared with 40% of those treated with placebo (P<0.01). Both patient and physician ratings of symptom severity, response to treatment, and overall condition of rhinitis indicated significant (P<0.01) superiority of MFNS over placebo. MFNS was well tolerated, with adverse events comparable to placebo. Conclusions: MFNS provided rapid onset of clinically significant symptom re lief in patients with seasonal allergic rhinitis.