The efficacy of short-term administration of 3 antihistamines vs placebo under natural exposure to Japanese cedar pollen.
BACKGROUND
Japanese cedar pollinosis, a common disease with morbidity of approximately 20% in the Japanese population, is characterized by subjectively irritating symptoms during an annual 3-month period.


OBJECTIVE
To investigate the effectiveness of cetirizine hydrochloride, loratadine, and fexofenadine hydrochloride in reducing pollinosis symptoms induced while walking in a park during the pollen season.


METHODS
A randomized, double-masked, placebo-controlled trial was conducted in 113 individuals with Japanese cedar pollinosis during 2 days in March 2003 in Osaka Expo Park, Osaka, Japan. Participants (aged 20-57 years) were divided into 4 groups according to treatment assignment: cetirizine hydrochloride, 10 mg/d; fexofenadine hydrochloride, 120 mg/d; loratadine, 10 mg/d; and placebo (lactose), twice daily. Symptoms were recorded hourly during the study. Furthermore, all the patients completed the Japanese version of the Rhinoconjunctivitis Quality of Life Questionnaire before and after the trial.


RESULTS
Self-evaluated symptom scores in all 3 active treatment groups showed significant improvements compared with the placebo group. Furthermore, the cetirizine group showed significant improvement in the domains of frequency of nose blowing and nasal obstruction compared with placebo. In addition, improvement in Japanese Rhinoconjunctivitis Quality of Life Questionnaire scores was higher in the cetirizine group than in the loratadine and placebo groups.


CONCLUSIONS
Cetirizine seems to be more effective than fexofenadine and loratadine at reducing subjective symptoms in this study population.
Hyo
Sawako
S
Department of Otorhinolaryngology, Osaka Medical College, Osaka, Japan. oto039@poh.osaka-med.ac.jp
Fujieda
Shigeharu
S
Kawada
Ryo
R
Kitazawa
Shikifumi
S
Takenaka
Hiroshi
H
D000328:Adult; D017332:Cetirizine / Q000627:therapeutic use; D032485:Cryptomeria / Q000276:immunology*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D039563:Histamine H1 Antagonists, Non-Sedating / Q000627:therapeutic use*; D006801:Humans; D007564:Japan; D017336:Loratadine / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011058:Pollen / Q000276:immunology*; D011788:Quality of Life; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy* / Q000276:immunology; D012912:Sneezing / Q000187:drug effects; D011795:Surveys and Questionnaires; D016593:Terfenadine / Q000031:analogs & derivatives* / Q000627:therapeutic use
D039563:Histamine H1 Antagonists, Non-Sedating; D017336:Loratadine; D016593:Terfenadine; C093230:fexofenadine; D017332:Cetirizine