Topical glucocorticoids with improved risk-benefit ratio. Rationale of a new concept

Topical glucocorticoids for dermal application were introduced more than 40 years ago and revolutionised the treatment of inflammatory skin diseases. Today these drugs are frequently administered, although systemic and local adverse drug reactions, especially skin atrophy, are feared complications of their use. This literature review evaluates the present state of topical glucocorticoid therapy for inflammatory skin diseases. Several attempts have been made to increase the safety of topical glucocorticoid treatment. With respect to conventional compounds, new application schedules, as well as new vehicles, have been proposed. New derivatives have also been synthesized, forming the novel group of nonhalogenated double-ester-type glucocorticoids. Among these latter compounds, prednicarbate and 6-methyl-prednisolone aceponate have been characterised most thoroughly. According to in vivo studies, their anti-inflammatory activity is in the order of that of betamethasone valerate (a frequently used medium potency glucocorticoid, which is obtained by halogenation of the pregnane nucleus of the steroid molecule). Furthermore, these new congeners induce less skin atrophy than conventional glucocorticoids, as determined by in vivo and in vitro studies. Qualitative and quantitative assessment of the therapeutic and adverse effects of non-halogenated double-ester-type glucocorticoids suggests an increased benefit-to-risk ratio.