Advances in single-entity inhaled corticosteroid therapy.

The aim of inhaled corticosteroid (ICS) therapy is to achieve optimal drug targeting by producing pulmonary effects with a minimum of systemic side effects. To achieve a favorable safety and efficacy profile, an ICS should possess the necessary pharmacokinetic and pharmacodynamic characteristics. Ideally, an ICS would have high pulmonary deposition efficiency, high systemic clearance, negligible oral bioavailability, sustained pulmonary residence time, selective binding to the corticosteroid receptor, and high plasma protein binding. Recent developments in ICS therapy have used these concepts in producing more effective compounds resulting in drugs with a very high therapeutic index. Additional developments may consider exploring improvements in delivery devices and drug formulations to improve pulmonary residence time.