Soft steroids: a new approach to the treatment of inflammatory airways diseases.

Inhaled synthetic glucocorticosteroids are widely used in the treatment of bronchial asthma where they provide very effective first line treatment. However, a range of unwanted side effects and the often complex dosing schedules associated with these drugs frequently result in poor patient compliance. The soft drug approach has been utilised as a means of delivering these potent anti-inflammatory agents close to their site of action while reducing the degree of systemic exposure and thus limiting or eliminating the associated systemic and local side effects. A further target for pharmaceutical companies is to deliver these new treatments in a once daily formulation thus further enhancing patient compliance. While many soft steroids have failed to progress into the clinic two are meeting with some degree of success. Loteprednol etabonate, an inactive metabolite soft steroid, has been accepted for the treatment of ophthalmic disorders and is being examined in clinical trials for its effects on airway inflammation. Ciclesonide, a pro-drug soft steroid, has demonstrated efficacy without side effects in a once daily formulation in asthma patients and is being developed for the treatment of both asthma and chronic obstructive pulmonary disease with launches of a once daily inhaler formulation expected in 2003. These drugs may represent a significant step forward in the treatment of inflammatory diseases of the airways.