Multicenter Prospective Observational Study to Evaluate the Therapeutic Effect and Safety of a Combination of Montelukast and Levocetirizine for Allergic Rhinitis when Administered to Patients with Allergic Rhinitis and Asthma

Introduction: Allergic rhinitis and asthma share a common inflammatory mechanism and are closely related, recognized as "one airway disease."Thus, the guidelines recommend allergic rhinitis and asthma be treated together, and leukotriene antagonists and antihistamines have been administered simultaneously; however, there are few reports of the use of combination drugs so far. Methods: The aim of the study was to evaluate the treatment effects and adverse events of Monterizine® (a combination of montelukast and levocetirizine); a total of 2,254 patients with perennial allergic rhinitis and asthma were prospectively enrolled from 60 hospitals nationwide in Korea. They were followed up for 3 (Period 1) or 6 months (Period 2). Total nasal symptom score (TNSS), satisfaction, and safety data were collected and compared to baseline. Results: TNSS scores were analyzed for 2,254 subjects. At Period 1 (n = 2,024) and 2 (n = 1,861), the scores decreased significantly from baseline (-1.20 ± 2.49 and -1.63 ± 2.78, p < 0.001). The mean quality of life (QoL) was significantly improved at Period 1 and 2 relative to baseline (-3.75 ± 6.58, -4.83 ± 7.11, both p < 0.0001). There were no serious adverse drug reactions, but there were some minor reactions including nasopharyngitis (2.92%), rhinitis (0.37%), and somnolence (0.34%). Conclusions: TNSS score and QoL were significantly improved by 3-6 months' treatment with Monterizine without significant adverse reactions. These results indicate that Monterizine, as a combination drug, is effective and safe for improving nasal symptoms and quality of life in patients with allergic rhinitis who also have asthma.