Intranasal
corticosteroids have been shown to be more effective than oral
antihistamines for the treatment of
seasonal allergic rhinitis. However, there are some who question whether intranasally administered
corticosteroids should be used due to potential systemic effects.
Fluticasone propionate, a potent
corticosteroid with high specificity for the
glucocorticoid receptor, is available as an aqueous
nasal spray for the treatment of
allergic rhinitis. To determine whether the efficacy of
fluticasone propionate aqueous
nasal spray (FPANS) was due to direct topical effects on the nasal mucosa or to indirect systemic effects following absorption from the nasal mucosa or from the swallowed portion of an intranasal dose, FPANS 200 micrograms once daily was compared with oral
fluticasone propionate 5 mg or 10 mg once daily or placebo for 2 weeks in patients with
seasonal allergic rhinitis. These oral dosages were chosen to yield low but consistent plasma
fluticasone propionate concentrations. Both clinician- and patient-rated scores for
nasal obstruction, rhinorrhoea,
sneezing, and nasal
itching were significantly lower in the intranasal
fluticasone propionate group compared with both oral
fluticasone propionate groups. A separate placebo-controlled study was conducted in patients with perennial
rhinitis to determine if administration of FPANS 200 micrograms once daily for 1 year was associated with adverse systemic effects. At the 1-year assessment, there were no significant effects on bone mineral density or on
biochemical markers of bone turnover. Similarly, there was no evidence of posterior subcapsular
cataracts nor of
glaucoma. Furthermore, there were no significant effects on hypothalamic-pituitary adrenal axis function as assessed by plasma
cortisol and 24-h urinary
cortisol response to the 6-h
cosyntropin stimulation test. These data confirm that the efficacy of FPANS for the treatment of
allergic rhinitis results from direct topical effects, thus reducing the likelihood of adverse systemic effects.