Further improvement of quality of life by cetirizine in perennial allergic rhinitis as a function of treatment duration.

The SF-36 Health Status Questionnaire is a generic quality of life questionnaire based on 36 questions selected to represent nine health concepts. Perennial allergic rhinitis is a disease which causes variable restrictions on the physical, psychological and social aspects of patients' lives. According to the SF-36 questionnaire assessment, quality of life is impaired in these patients. Cetirizine, a potent, reliable histamine H1-receptor antagonist, has already been found to induce significant improvement in the quality of life of patients with chronic rhinitis, as assessed by the same SF-36 questionnaire after 1 and 6 weeks of treatment. This paper further investigates the extent to which cetirizine continues to improve quality of life after a long-term treatment (6 weeks) compared to a shorter treatment (1 week). The analyses show that, despite the significant improvement found after 1 week of treatment with cetirizine compared to placebo, a further 5-week course of therapy not only maintains this improvement but continues to enhance quality of life significantly above and beyond this.