The precise mechanism through which fluticasone propionate affects rhinitis symptoms is not known. Corticosteroids have been shown to have a wide range of effects on multiple cell types (., mast cells, eosinophils, neutrophils, macrophages, lymphocytes) and mediators (., histamine, eicosanoids, leukotrienes, cytokines) involved in inflammation. In 7 trials in adults, Flonase Nasal Spray has decreased nasal mucosal eosinophils in 66% of patients (35% for placebo) and basophils in 39% of patients (28% for placebo). The direct relationship of these findings to long-term symptom relief is not known.
40 mcg inhaled twice daily, approximately 12 hours apart, is the recommended starting dose. For patients who do not respond adequately to 40 mcg after 2 weeks of therapy, increasing the dosage to 80 mcg twice daily may provide additional asthma control. The maximum recommended dosage is 80 mcg twice daily. The starting dosage is based on the severity of asthma, including consideration of the patients’ current control of asthma symptoms and risk of future exacerbation. Improvement in asthma symptoms can occur within 24 hours of the beginning of treatment and should be expected within the first or second week, but maximum benefit should not be expected until 3 to 4 weeks of therapy. Improvement in pulmonary function is usually apparent within 1 to 4 weeks after the start of therapy. The National Asthma Education and Prevention Program Expert Panel defines low dose therapy as 80 to 160 mcg/day, medium dose as 161 to 320 mcg/day, and high dose therapy as more than 320 mcg/day for children ages 5 to 11 years. The Global Initiative for Asthma (GINA) guidelines define low dose therapy as 100 mcg/day in this age group. Titrate to the lowest effective dose once asthma stability is achieved.