title: Efficacy comparison of levocetirizine vs montelukast in ragweed sensitized patients.
abstract: BACKGROUND
  To date, no adequate data are available on direct comparison of the efficacy of levocetirizine, a recently approved histamine1-antihistamine, with that of a leukotriene antagonist in the treatment of seasonal allergic rhinitis (SAR) symptoms.
  
  
  OBJECTIVE
  To compare the efficacy of therapeutic doses of 5 mg of levocetirizine and 10 mg of montelukast in ragweed sensitized patients.
  
  
  METHODS
  A randomized, double-blind, placebo-controlled, parallel-group study was conducted between July and October 2006. Symptomatic patients with SAR were exposed to ragweed pollen under controlled conditions in an environmental exposure chamber for 4 to 5 hours after treatment with 5 mg of levocetirizine, 10 mg of montelukast, or matched placebo on 2 consecutive days. The mean change from baseline in pollen-induced rhinitis symptoms, expressed as a major symptoms complex (MSC) score (sum of scores for rhinorrhea, itchy nose, sniffles, nose blows, sneezes, and watery eyes), in period 1 (first 5 hours after first drug intake) was the primary efficacy outcome.
  
  
  RESULTS
  A total of 611 patients were screened, of whom 403 were randomized to receive treatment (102 placebo, 152 levocetirizine, and 149 montelukast). The MSC score in period 1 was progressively decreased to a significantly greater extent in the levocetirizine group compared with the montelukast and placebo groups (adjusted mean differences, -2.18 [95% confidence interval, -3.35 to -1.01; P < .001] and -2.22 [95% confidence interval, -3.51 to -0.92; P < .001] for levocetirizine vs montelukast and vs placebo, respectively). The effect of 10 mg of montelukast was not significantly different compared with placebo. Levocetirizine also achieved a significantly faster onset of action within 2.5 hours of administration. Both products were well tolerated.
  
  
  CONCLUSIONS
  This study in an environmental exposure chamber confirms the therapeutic efficacy of 5 mg of levocetirizine in improving symptoms of SAR, which was superior to 10 mg of montelukast.
authors.affiliation: Allied Research International, Cetero Research, Mississauga, Ontario, Canada. ppatel@allied-research.com
authors.forename: Piyush
authors.initials: P
authors.lastname: Patel
authors.forename: Deepen
authors.initials: D
authors.lastname: Patel
mesh_terms: D015746:Abdominal Pain / Q000139:chemically induced; D000085:Acetates / Q000009:adverse effects / Q000627:therapeutic use*; D000293:Adolescent; D000328:Adult; D000368:Aged; D031164:Ambrosia / Q000276:immunology*; D017332:Cetirizine / Q000009:adverse effects / Q000627:therapeutic use*; D003521:Cyclopropanes; D004311:Double-Blind Method; D005076:Exanthema / Q000139:chemically induced; D005260:Female; D039563:Histamine H1 Antagonists, Non-Sedating / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D020024:Leukotriene Antagonists / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011804:Quinolines / Q000009:adverse effects / Q000627:therapeutic use*; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy* / Q000276:immunology; D013440:Sulfides; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000085:Acetates; D003521:Cyclopropanes; D039563:Histamine H1 Antagonists, Non-Sedating; D020024:Leukotriene Antagonists; D011804:Quinolines; D013440:Sulfides; C472067:levocetirizine; C093875:montelukast; D017332:Cetirizine