title: Onset of action of loratadine/montelukast in seasonal allergic rhinitis subjects exposed to ragweed pollen in the Environmental Exposure Unit.
abstract: Onset of action is recognized as an important pharmacologic property of allergic rhinitis (AR) medications. This study was designed to evaluate the onset of action of loratadine/montelukast (L/M; 10 mg/10 mg) versus placebo in subjects with ragweed-induced seasonal AR (SAR). A single-center, double-blind, parallel-group study of ragweed-sensitive AR subjects (n = 310) was performed in the Environmental Exposure Unit (EEU). Subjects were exposed to ragweed pollen in the EEU and symptoms were recorded at 30, 60, 90, and 120 minutes before a single dose of L/M or placebo. After dosing, symptoms were recorded for 4 hours, at 15-minute intervals for the first 2 hours and at 30-minute intervals for the final 2 hours. The primary end point was time to onset of action of L/M, defined as the first time point at which the mean change from baseline in total symptom score (TSS) for L/M became and remained significantly better than placebo. Secondary end points included nasal congestion scores and peak nasal inspiratory flow (PNIF). The onset of action of L/M for TSS was 1 hour and 15 minutes (p = 0.005 versus placebo). L/M reduced nasal congestion as indicated by significant improvements in both the nasal congestion score (p = 0.011) and the PNIF measurements (p = 0.007) within 1 hour and 15 minutes postdose. The incidence of treatment-emergent adverse events was similar between groups. The onset of action after treatment with L/M was 1 hour and 15 minutes for TSS, as well as nasal congestion. L/M was well tolerated.
authors: Department of Medicine, Queen's University and Division of Allergy and Immunology, Kingston General Hospital, Kingston, Ontario, Canada. dayj@kgh.kari.net
authors: James H
authors: JH
authors: Day
authors: Maureen P
authors: MP
authors: Briscoe
authors: Jodan D
authors: JD
authors: Ratz
authors: Anne K
authors: AK
authors: Ellis
authors: Ruji
authors: R
authors: Yao
authors: Melvyn
authors: M
authors: Danzig
mesh_terms: D000085:Acetates / Q000008:administration & dosage / Q000627:therapeutic use*; D000328:Adult; D000485:Allergens / Q000276:immunology; D031164:Ambrosia / Q000276:immunology*; D018926:Anti-Allergic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D003521:Cyclopropanes; D004311:Double-Blind Method; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D017336:Loratadine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D011058:Pollen / Q000276:immunology*; D011804:Quinolines / Q000008:administration & dosage / Q000627:therapeutic use*; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy* / Q000276:immunology; D013440:Sulfides
chemical_list: D000085:Acetates; D000485:Allergens; D018926:Anti-Allergic Agents; D003521:Cyclopropanes; D011804:Quinolines; D013440:Sulfides; D017336:Loratadine; C093875:montelukast