Compare the Efficacy of Levocetirizine and Montelukast to Placebo in Reducing Seasonal Allergic Rhinitis (SAR) Symptoms in Ragweed Sensitive Subjects

Six individual symptoms which are most dominant in the rhinitis symptom profile will be combined to form the MSC severity score: Runny nose (right and left), itchy nose (right and left), sniffles, nose blows, sneezes, watery eyes. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The total MSC score ranges from 0 - 36. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

Six individual symptoms which are most dominant in the rhinitis symptom profile will be combined to form the MSC severity score: Runny nose (right and left), itchy nose (right and left), sniffles, nose blows, sneezes, watery eyes. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The total MSC score ranges from 0 - 36. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

Six individual symptoms which are most dominant in the rhinitis symptom profile will be combined to form the MSC severity score: Runny nose (right and left), itchy nose (right and left), sniffles, nose blows, sneezes, watery eyes. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The total MSC score ranges from 0 - 36. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

Six individual symptoms which are most dominant in the rhinitis symptom profile will be combined to form the MSC severity score: Runny nose (right and left), itchy nose (right and left), sniffles, nose blows, sneezes, watery eyes. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The total MSC score ranges from 0 - 36. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

The TSC score was calculated as the sum of the following 10 individual symptom scores: runny nose (left and right), itchy nose (left and right), sniffles, nose blows, sneezes, watery eyes, itchy eyes and ears, itchy throat, cough and postnasal drip. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The TSC score ranges from 0 to 56. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

The TSC score was calculated as the sum of the following 10 individual symptom scores: runny nose (left and right), itchy nose (left and right), sniffles, nose blows, sneezes, watery eyes, itchy eyes and ears, itchy throat, cough and postnasal drip. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The TSC score ranges from 0 to 56. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

The TSC score was calculated as the sum of the following 10 individual symptom scores: runny nose (left and right), itchy nose (left and right), sniffles, nose blows, sneezes, watery eyes, itchy eyes and ears, itchy throat, cough and postnasal drip. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The TSC score ranges from 0 to 56. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

The TSC score was calculated as the sum of the following 10 individual symptom scores: runny nose (left and right), itchy nose (left and right), sniffles, nose blows, sneezes, watery eyes, itchy eyes and ears, itchy throat, cough and postnasal drip. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The TSC score ranges from 0 to 56. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

The TSC score was calculated as the sum of the following 10 individual symptom scores: runny nose (left and right), itchy nose (left and right), sniffles, nose blows, sneezes, watery eyes, itchy eyes and ears, itchy throat, cough and postnasal drip. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The Nasal congestion score ranged from 0 to 4 (0 = clear, 1 = slight block, 2 = stuffy, 3 = very stuffy, 4 = blocked). It corresponds to the mean value of right nostril and left nostril. The TSC score plus Nasal congestion score was added and ranged from 0 to 60. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

The TSC score was calculated as the sum of the following 10 individual symptom scores: runny nose (left and right), itchy nose (left and right), sniffles, nose blows, sneezes, watery eyes, itchy eyes and ears, itchy throat, cough and postnasal drip. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The Nasal congestion score ranged from 0 to 4 (0 = clear, 1 = slight block, 2 = stuffy, 3 = very stuffy, 4 = blocked). It corresponds to the mean value of right nostril and left nostril. The TSC score plus Nasal congestion score was added and ranged from 0 to 60. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

The TSC score was calculated as the sum of the following 10 individual symptom scores: runny nose (left and right), itchy nose (left and right), sniffles, nose blows, sneezes, watery eyes, itchy eyes and ears, itchy throat, cough and postnasal drip. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The Nasal congestion score ranged from 0 to 4 (0 = clear, 1 = slight block, 2 = stuffy, 3 = very stuffy, 4 = blocked). It corresponds to the mean value of right nostril and left nostril. The TSC score plus Nasal congestion score was added and ranged from 0 to 60. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

The TSC score was calculated as the sum of the following 10 individual symptom scores: runny nose (left and right), itchy nose (left and right), sniffles, nose blows, sneezes, watery eyes, itchy eyes and ears, itchy throat, cough and postnasal drip. Each individual symptom, except nose blows and sneezes, is rated on a 5-point scale of severity: 0 = None, 1 = a little, 2 = Moderate, 3 = Quite a bit, 4 = severe, 5 = very severe. For nose blows and sneezes, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The Nasal congestion score ranged from 0 to 4 (0 = clear, 1 = slight block, 2 = stuffy, 3 = very stuffy, 4 = blocked). It corresponds to the mean value of right nostril and left nostril. The TSC score plus Nasal congestion score was added and ranged from 0 to 60. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

Individual symptom scores include Runny Nose Score, Itchy Nose Score, Sniffles Score, Postnasal Drip Score, Watery Eyes Score, Itchy Eyes and Ears Score, Itchy Throat Score, Cough Score, Sneezes Score, Nose Blows Score, Nasal Congestion Score. The subjects had to evaluate the severity of the symptoms using a scale from "None" to "Very severe" (ranging from 0 to 5). For Sneezes Score and Nose Blows Score, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The Nasal congestion score ranged from 0 to 4 (0 = clear, 1 = slight block, 2 = stuffy, 3 = very stuffy, 4 = blocked). It corresponds to the mean value of right nostril and left nostril. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

Individual symptom scores include Runny Nose Score, Itchy Nose Score, Sniffles Score, Postnasal Drip Score, Watery Eyes Score, Itchy Eyes and Ears Score, Itchy Throat Score, Cough Score, Sneezes Score, Nose Blows Score, Nasal Congestion Score. The subjects had to evaluate the severity of the symptoms using a scale from "None" to "Very severe" (ranging from 0 to 5). For Sneezes Score and Nose Blows Score, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The Nasal congestion score ranged from 0 to 4 (0 = clear, 1 = slight block, 2 = stuffy, 3 = very stuffy, 4 = blocked). It corresponds to the mean value of right nostril and left nostril. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

Individual symptom scores include Runny Nose Score, Itchy Nose Score, Sniffles Score, Postnasal Drip Score, Watery Eyes Score, Itchy Eyes and Ears Score, Itchy Throat Score, Cough Score, Sneezes Score, Nose Blows Score, Nasal Congestion Score. The subjects had to evaluate the severity of the symptoms using a scale from "None" to "Very severe" (ranging from 0 to 5). For Sneezes Score and Nose Blows Score, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The Nasal congestion score ranged from 0 to 4 (0 = clear, 1 = slight block, 2 = stuffy, 3 = very stuffy, 4 = blocked). It corresponds to the mean value of right nostril and left nostril. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

Individual symptom scores include Runny Nose Score, Itchy Nose Score, Sniffles Score, Postnasal Drip Score, Watery Eyes Score, Itchy Eyes and Ears Score, Itchy Throat Score, Cough Score, Sneezes Score, Nose Blows Score, Nasal Congestion Score. The subjects had to evaluate the severity of the symptoms using a scale from "None" to "Very severe" (ranging from 0 to 5). For Sneezes Score and Nose Blows Score, the subjects had to record the number of each symptom since last evaluation. This number corresponds to a score ranging from 0 to 8. The Nasal congestion score ranged from 0 to 4 (0 = clear, 1 = slight block, 2 = stuffy, 3 = very stuffy, 4 = blocked). It corresponds to the mean value of right nostril and left nostril. Increasing scores are associated with increasing severity. Negative values indicate improvement from Baseline.

During Period I, the subjects had to record the moment (hh:mm) of first feeling of improvement (compared to Baseline intensity of symptoms).

The onset of action was defined as the first time point during Period I after initiation of the treatment when the reduction from Baseline in the MSC score for the active treatment group became statistically different from the placebo group and when this significant change was maintained for some period of time.

The intensity of action was measured by the percentage of subjects with categorized percentage change from Baseline in the MSC score over Period I. Categories are defined as following: < 20%, >=20%, < 50%, >=50%, < 70%, >=70% change from Baseline.

The intensity of action was measured by the percentage of subjects with categorized percentage change from Baseline in the MSC score over Period II. Categories are defined as following: < 20%, >=20%, < 50%, >=50%, < 70%, >=70% change from Baseline.

The intensity of action was measured by the percentage of subjects with categorized percentage change from Baseline in the MSC score over Period III. Categories are defined as following: < 20%, >=20%, < 50%, >=50%, < 70%, >=70% change from Baseline.

The variability of action was assessed by the percentage of distribution of the percentage change from Baseline in the MSC score. Categories are defined as following: < 20%, 20%-35%, 35%-50%, 50%-65%, 65%-80%, >=80%.

The variability of action was assessed by the percentage of distribution of the percentage change from Baseline in the MSC score. Categories are defined as following: < 20%, 20%-35%, 35%-50%, 50%-65%, 65%-80%, >=80%.

The variability of action was assessed by the percentage of distribution of the percentage change from Baseline in the MSC score. Categories are defined as following: < 20%, 20%-35%, 35%-50%, 50%-65%, 65%-80%, >=80%.

Global satisfaction was evaluated at the end of Period III by the subject on a Visual Analog Scale (VAS) ranging from 0 (very dissatisfied) to 100 mm (very satisfied).

At the end of Period III, each subject without reference to the Symptom Diary Card (SDC) answered to the question: "Do you want to take the same treatment during the next pollen season?" (yes or no).