BB and FEX, in comparison to PL, were equally effective in attenuating the nasal response to AMP and in improving nasal symptoms, highlighting a potential role for BB in the treatment of allergic rhinitis.

There was a highly significant association between the threshold concentration of AMP and dose of mannitol causing a given fall in FEV1. Further studies are required to evaluate the relationship between inhaled mannitol and other surrogate inflammatory markers.

BB exhibited protection against AMP-induced nasal responsiveness during the grass pollen season in sensitized patients. This is turn may explain its potential clinical efficacy in patients with SAR.