Expected characteristics of an ideal, all-purpose inhaled corticosteroid for the treatment of asthma.

BACKGROUND

Inhaled corticosteroids (ICSs) are well established as the mainstay of asthma therapy. A number of ICSs are now available, each with unique pharmacokinetic/pharmacodynamic profiles and physical characteristics.

OBJECTIVE

This article reviews the key characteristics of an ideal ICS and uses examples of existing agents to indicate the extent to which therapies reach these goals.

RESULTS

Improved therapeutic efficacy in an ICS may be offset by an increase in systemic effects. The ideal characteristics of an ICS include optimal clinical efficacy and no toxicity in combination with a convenient and easy-to-use inhaler device. To achieve this optimal profile, an ICS should have the following: a high affinity for and potency at the glucocorticoid receptor; prolonged retention in the lung; minimal or no oral bioavailability (ie, high first-pass inactivation); and rapid, complete systemic inactivation. The formulation and type of inhaler device are also important considerations: they should provide deposition in the lung in both large and small airways with no absorption effects outside the lung. ICSs should be evaluated for administration with several different delivery devices to ensure ease of use by patients of all ages with different asthma severities. An ICS that can be administered QD is also likely to improve patient adherence by simplifying the treatment regimen.

CONCLUSION

An ideal ICS should have a large therapeutic margin, be used safely and effectively for long periods, be administered QD, be suitable for use in patients of all ages and asthma severities, and offer both control and prevention of asthma symptoms and exacerbations.