Biological availability of inhaled fluticasone propionate in horses

Healthy horses received aerosolised, intranasal or oral doses of 3 mg of fluticasone propionate evenly divided over morning and evening treatments for seven days. The bioavailability of the drug was determined in terms of the suppression of the endogenous cortisol concentrations in the horses during the period of treatment. The horses which received the aerosolised drug had significantly lower concentrations of endogenous cortisol on days 5 and 8 than the horses which received aerosolised placebo. The horses which received nasal and oral doses of fluticasone propionate showed no significant changes in their endogenous cortisol concentrations.