Efficacy and Safety of Concomitant Montelukast Sodium and Levocetirizine Dihydrochloride in Perennial Allergic Rhinitis (PAR) Patients

randomized, double-blind, active-controlled, multicenter, phase 3 trial

Inclusion criteria

• Patients with at least 2 years history of PAR prior to the study
• Positive results of skin prick test
• Patients who provided a signed written informed consent form
• Patients who are able and willing to complete subject diaries
• Patients who agree to maintain consistency in their surroundings throughout the study period
• At Visit, 2 patients whose symptom scores recorded in the subject diary meet all of the followings during the last one week of baseline period A.Daily mean of 6 points or above for Daytime Nasal Symptom Score (maximum 12 points) B.Daily mean of 1.8 points or above for Daytime Nasal Obstruction Symptom Score (maximum 3 points)

Exclusion criteria

• Patients also with non-allergic rhinitis with different causes.
• Patients with severe asthma who meet the followings.
• Presence of nasal polyps or any clinically important nasal anomaly.
• History of acute • chronic sinusitis within 30 days of Visit 1
• History of intranasal / eye surgeries within 3 months of Visit 1
• Initiation of immunotherapy or dose modification within 1 month prior to Visit 1
• Upper respiratory infections including cold and systemic infections within 3 weeks of Visit 1.
• Chronic use of tricyclic antidepressants, beta agonists, bronchodilators, etc. that may affect the efficacy of study drug
• At Visit 2, patients who recorded Daytime Nasal Symptom Scores for fewer than 4 days in the subject diary during the last one week of baseline period