A double-blind, randomized, parallel-group, placebo-controlled study involving 130 patients was conducted at 9 centres in the U.K. to assess the effect of 6 weeks of treatment with azelastine nasal spray (azelastine) and beclomethasone dipropionate nasal spray (BDP) on the symptoms of perennial rhinitis. Efficacy was assessed by patients recording daily the severity of the symptoms of rhinitis on 10-cm visual analogue scales. Analysis of this diary data showed significant reductions in sneezing, blocked nose, running nose, and itching nose during azelastine treatment. Patients on BDP recorded a consistent reduction in rhinitis symptoms, but these reductions were significant only for sneezing on treatment day 7. When rhinitis symptoms were assessed by clinical investigators on a 4-point scale, the scores obtained following treatment with the 2 study medications showed little change from baseline or "active" treatment scores. There was no evidence of a consistent change in nasal airway resistance, measured using anterior rhinomanometry, following treatment with either BDP or azelastine. Azelastine nasal spray and BDP nasal spray were well tolerated by the patients and the relative incidence of adverse events was similar in the azelastine and placebo/azelastine treatment groups, except that taste perversion occurred more frequently during azelastine treatment than during placebo/azelastine treatment. There was no evidence of an increased incidence of somnolence or fatigue in patients who received azelastine nasal spray. Overall, the results of this study indicate that azelastine administered twice daily as an intranasal spray is a safe and efficacious treatment for the symptoms of rhinitis in patients suffering from mild to moderate perennial rhinitis.