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Xyzal

Clinical Pharmacology
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Clinical Pharmacology

One clinical trial was designed to evaluate the efficacy of XYZAL 5 mg once daily in the evening compared with placebo in patients with seasonal allergic rhinitis over a 2-week treatment period. In this trial, XYZAL 5 mg demonstrated a greater decrease from baseline in the reflective and instantaneous total symptom score than placebo, and the difference was statistically significant (see Table 4). The results of the instantaneous total symptom score support efficacy at the end of the dosing interval.

One clinical trial evaluated the efficacy of XYZAL 5 mg once daily in the evening compared to placebo in patients with perennial allergic rhinitis over a 6-week treatment period. Another trial conducted over a 6-month treatment period assessed efficacy at 4 weeks. XYZAL 5 mg demonstrated a greater decrease from baseline in the reflective total symptom score than placebo and the difference from placebo was statistically significant. Results of one of these trials are shown in Table 4.

Table 4: Mean Reflective Total Symptom Score* and Instantaneous Total Symptom Score in Allergic Rhinitis Trials

Treatment N Baseline On
Treatment
Adjusted
Mean
Difference from Placebo
Estimate 95% CI p-value
Seasonal Allergic Rhinitis Trial – Reflective total symptom score
XYZAL 5 mg 118 8.40 5.20 0.89 (0.30, 1.47) 0.003
Placebo 117 8.50 6.09      
Seasonal Allergic Rhinitis Trial – Instantaneous total symptom score
XYZAL 5 mg 118 7.24 4.58 0.73 (0.17, 1.28) 0.011
Placebo 117 7.48 5.30      
Perennial Allergic Rhinitis Trial – Reflective total symptom score
XYZAL 5 mg 150 7.69 3.93 1.17 (0.70, 1.64) <0.001
Placebo 142 7.44 5.10      
*Total symptom score is the sum of individual symptoms of sneezing, rhinorrhea, nasal pruritus, and ocular pruritus as assessed by patients on a 0-3 categorical severity scale.

Onset of action was evaluated in two environmental exposure unit studies in allergic rhinitis patients with a single dose of XYZAL 2.5 or 5 mg. XYZAL 5 mg was found to have an onset of action 1 hour after oral intake. Onset of action was also assessed from the daily recording of symptoms in the evening before dosing in the seasonal and perennial allergic rhinitis trials. In these trials, onset of effect was seen after 1 day of dosing.

Pediatric Patients Less than 12 Years of Age

There are no clinical trials with XYZAL 2.5 mg once daily in pediatric patients under 12 years of age [see Use in Specific Populations].

Chronic Idiopathic Urticaria

Adult Patients 18 Years of Age and Older

The efficacy of XYZAL for the treatment of the uncomplicated skin manifestations of chronic idiopathic urticaria was evaluated in two multi-center, randomized, placebo-controlled, double-blind clinical trials of 4 weeks duration in adult patients 18 to 85 years of age with chronic idiopathic urticaria. The two trials included one 4-week dose- ranging trial and one 4-week single-dose level efficacy trial. These trials included 423 patients (139 males and 284 females). Most patients (>90%) were Caucasian and the mean age was 41. Of these patients, 146 received XYZAL 5 mg once daily in the evening. Efficacy was assessed based on patient recording of pruritus severity on a severity score of 0–3 (0 = none to 3 = severe). The primary efficacy endpoint was the mean reflective pruritus severity score over the first week and over the entire treatment period. Additional efficacy variables were the instantaneous pruritus severity score, the number and size of wheals, and duration of pruritus.

Brand Name: Xyzal
Generic Name: Levocetirizine Dihydrochloride
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