Nonallergic perennial
rhinitis (also commonly referred to as
vasomotor rhinitis) is a chronic non-
IgE-mediated condition that is characterized by symptoms which are similar to those seen in
allergic rhinitis, but which persist for over nine months each year. Although treatment of
vasomotor rhinitis involves the use of either intranasal
corticosteroids or
antihistamines, the
corticosteroids are generally not effective in treatment of all the symptoms of
vasomotor rhinitis and have generally been shown to be effective in patients with
eosinophilia. With the exception of
azelastine, the only topical
antihistamine to be approved by the FDA for the treatment of nonallergic
rhinitis, the
antihistamines have also produced inconsistent results. While clinical studies of
azelastine have demonstrated that this
drug is highly efficacious in the treatment of all the symptoms of
vasomotor rhinitis, mechanistic studies have demonstrated that
azelastine has potent anti-inflammatory effects (in particular attenuation of the expression and synthesis of pro-inflammatory
cytokines,
leukotrienes, and
cell adhesion molecules), which are likely to contribute to its clinical efficacy. Furthermore, pharamacokinetic studies have suggested that since
azelastine has a more rapid onset of action, compared to most other
antihistamines and intranasal
corticosteroids, then
azelastine nasal spray may be considered as primary
therapy for patients with symptoms of both allergic and/or vasomotor (nonallergic perennial)
rhinitis.