title: Efficacy and safety of desloratadine in the treatment of perennial allergic rhinitis.
abstract: BACKGROUND
  The evidence base for the use of H1-antihistamines in the treatment of perennial allergic rhinitis is considerably smaller than it is in the treatment of seasonal allergic rhinitis.
  
  
  OBJECTIVE
  We hypothesized that desloratadine, a new, nonsedating selective H1-antihistamine, would be efficacious and safe in the treatment of perennial allergic rhinitis.
  
  
  METHODS
  In a multicenter, randomized, placebo-controlled, double-blind, parallel-group study, 676 patients with symptomatic perennial allergic rhinitis were randomly assigned to 4 weeks of treatment with either 5 mg of desloratadine once daily or placebo. Efficacy was assessed by using a morning-evening instantaneous total symptom score (TSS), which was composed of scores for 4 individual nasal symptoms (rhinorrhea, itching, sneezing, and postnasal drip) and 3 individual nonnasal symptoms (itching eyes, watering eyes, and itching of the ears or palate). Secondary outcome measures included a morning-evening reflective TSS, total nasal and nonnasal symptoms scores, and individual symptom scores. Safety evaluations, including 12-lead electrocardiograms, were performed.
  
  
  RESULTS
  Six hundred thirty-four patients completed the study. Desloratadine consistently diminished perennial allergic rhinitis symptoms, reducing the morning-evening instantaneous TSS (P =.005), the morning-evening reflective TSS (P =.007), the morning-evening reflective total nonnasal score (P =.023), and the individual nasal symptom scores for rhinorrhea, nasal itching, sneezing, and postnasal drip/drainage (P =.05 to P =.013) during weeks 1 through 4. Improvement in symptoms was observed after the first dose. Dropouts, and the type and frequency of adverse events (headache, viral infection, pharyngitis, and upper respiratory tract infection), were similar in both treatment groups. No clinically significant changes in QTc intervals were observed.
  
  
  CONCLUSIONS
  Desloratadine rapidly and safely reduced the symptoms of perennial allergic rhinitis, and its efficacy did not diminish during 4 weeks of treatment.
authors.affiliation: Section of Allergy and Clinical Immunology, Department of Pedia-trics and Child Health, University of Manitoba, Winnipeg, Canada.
authors.forename: F Estelle R
authors.initials: FE
authors.lastname: Simons
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Prenner
authors.forename: Albert
authors.initials: A
authors.lastname: Finn
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004311:Double-Blind Method; D005260:Female; D039563:Histamine H1 Antagonists, Non-Sedating / Q000009:adverse effects* / Q000627:therapeutic use*; D006801:Humans; D017336:Loratadine / Q000009:adverse effects* / Q000031:analogs & derivatives / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010352:Patient Dropouts; D012221:Rhinitis, Allergic, Perennial / Q000188:drug therapy*; D012449:Safety
chemical_list: D039563:Histamine H1 Antagonists, Non-Sedating; D017336:Loratadine; C121345:desloratadine