title: Comparative clinical efficacy, onset and duration of action of levocetirizine and desloratadine for symptoms of seasonal allergic rhinitis in subjects evaluated in the Environmental Exposure Unit (EEU).
abstract: The Environmental Exposure Unit, an indoor pollen challenge system to test anti-allergic medications, was used to compare the onset and duration of action and the efficacy of levocetirizine and desloratadine, two recently developed H1-antagonists. In this double-blind, placebo-controlled, parallel-group study, qualified subjects were randomised to once-daily levocetirizine 5 mg (n = 141), desloratadine 5 mg (n = 140) or placebo (n = 92) and exposed to ragweed pollen on two consecutive days (7 h and 6 h). Symptoms were self-rated every 30 min. On both days, levocetirizine produced a greater improvement in the major symptom complex score (primary efficacy variable) than desloratadine (p = 0.015); both were better than placebo (p < 0.001). Levocetirizine acted earlier (1 h vs. 3 h) and produced greater symptom relief at 24 h than desloratadine (p = 0.003). Levocetirizine also alleviated nasal obstruction better than desloratadine (p = 0.007) on day 1; and better than placebo (p = 0.014) after the second dose on day 2, which was not observed with desloratadine. Levocetirizine and desloratadine were safe and well tolerated.
authors.affiliation: Division of Allergy and Immunology, Kingston General Hospital, Kingston, Ontario, Canada. dayj@kgh.kari.net
authors.forename: J H
authors.initials: JH
authors.lastname: Day
authors.forename: M P
authors.initials: MP
authors.lastname: Briscoe
authors.forename: E
authors.initials: E
authors.lastname: Rafeiro
authors.forename: J D
authors.initials: JD
authors.lastname: Ratz
mesh_terms: D000293:Adolescent; D000328:Adult; D017332:Cetirizine / Q000627:therapeutic use*; D015331:Cohort Studies; D004311:Double-Blind Method; D005260:Female; D039563:Histamine H1 Antagonists, Non-Sedating / Q000627:therapeutic use*; D006801:Humans; D017336:Loratadine / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D008297:Male; D010879:Piperazines / Q000627:therapeutic use*; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy*; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D039563:Histamine H1 Antagonists, Non-Sedating; D010879:Piperazines; C472067:levocetirizine; D017336:Loratadine; C121345:desloratadine; D017332:Cetirizine