Possibilities in improvement of glucocorticoid treatments in asthma with special reference to loteprednol etabonate

Allergic conditions contribute significantly to the burden of chronic disease in the industrialized world. The increasing prevalence has lead research into the discovery and development of various new therapeutic strategies. Despite considerable efforts of the pharmaceutical industry, the leukotriene antagonists were the only new class of asthma treatments to be licensed in the past 30 years. Topical glucocorticoids (GCs) are the most potent and effective therapy for treating allergic diseases. However, their use is limited by diverse undesired effects. Changes in pharmacokinetic parameters of GCs may be an interesting and promising approach to improve efficacy and safety of inhaled GCs. Loteprednol etabonate has been developed on the basis of the retrometabolic drug design. In animal studies, it has been demonstrated to have long-lasting anti-allergic (anti-asthmatic) effects without influencing the hypothalamic-pituitary axis (HPA). This soft steroid is now in phase III of the clinical development. Recently, loteprednol has been proven to be effective in the management of allergic rhinitis (400 microg once daily). No suppression of HPA was observed at clinically effective and higher doses. In conclusion, loteprednol as the first representative of soft steroids elicits marked anti-inflammatory effects, but has no impact on endocrine responses. It may represent a promising new therapy in the treatment of allergic rhinitis and asthma.