Initial dose based on previous asthma drug therapy and disease severity; 100 mcg via oral inhalation once daily is the usual recommended starting dose for patients not on an inhaled corticosteroid. After 2 weeks of therapy, if asthma symptoms are uncontrolled, increase dose to 200 mcg via oral inhalation once daily. Max: 200 mcg once daily. Administer at the same time each day. The maximum beneficial effect may not be achieved for up to 2 weeks or longer after starting treatment. Titrate to the lowest effective dose once asthma stability is achieved.
In rare cases, patients on inhaled fluticasone propionate may present with systemic eosinophilic conditions. Some of these patients have clinical features of vasculitis consistent with Churg-Strauss syndrome , a condition that is often treated with systemic corticosteroid therapy. These events usually, but not always, have been associated with the reduction and/or withdrawal of oral corticosteroid therapy following the introduction of fluticasone propionate. Cases of serious eosinophilic conditions have also been reported with other inhaled corticosteroids in this clinical setting. Physicians should be alert to eosinophilia , vasculitic rash, worsening pulmonary symptoms, cardiac complications, and/or neuropathy presenting in their patients. A causal relationship between fluticasone propionate and these underlying conditions has not been established.
No metabolites of fluticasone propionate were detected in an in vitro study of radiolabeled fluticasone propionate incubated in a human skin homogenate. The total blood clearance of systemically absorbed fluticasone propionate averages 1,093 mL/min (range, 618 to 1,702 mL/min) after a 1-mg intravenous dose, with renal clearance accounting for less than % of the total. Fluticasone propionate is metabolized in the liver by cytochrome P450 3A4-mediated hydrolysis of the 5- fluoromethyl carbothioate grouping. This transformation occurs in 1 metabolic step to produce the inactive17-ÃŸ-carboxylic acid metabolite, the only known metabolite detected in man. This metabolite has approximately 2,000 times less affinity than the parent drug for the glucocorticoid receptor of human lung cytosol in vitro and negligible pharmacological activity in animal studies. Other metabolites detected in vitro using cultured human hepatoma cells have not been detected in man.