Glucocorticosteroids inhibit the disposal of organic cations by blocking organic cation transporters expressed by non-neuronal cells, thereby interfering with the inactivation of the organic cations by intracellular enzymes. Beta2-adrenergic agonists are organic cations, and the concentration of inhaled beta2-adrenergic agonists at beta2-adrenergic receptor sites on smooth muscle is likely to be increased by inhaled glucocorticosteroids (ICS) by the ICS' effect on the glucocorticosteroid-sensitive organic cation transporters. The investigators have shown in human airway vascular smooth muscle cells that the glucocorticosteroid action on organic cation uptake occurs within minutes, does not involve gene transcription or protein synthesis, is not mediated through classical steroid receptors, and is cell membrane-linked.