Low bioavailability and traditional systemic steroids in IBD: can the former take over the latter?

Systemic corticosteroids have been used to treat active inflammatory bowel disease for over 50 years by virtue of their unquestionable efficacy in inducing clinical remission rapidly in the vast majority of patients. Nevertheless, traditional corticosteroids are associated to a plethora of potentially serious side effects due to their systemic metabolism; for this reason, interest has lately been growing in newer steroid compounds characterized by a high topical anti-inflammatory activity and a low systemic bioavailability. These compounds, namely budesonide and beclomethasone dipropionate--regarding the treatment of inflammatory bowel disease--can be administered orally and thanks to sophisticated delivery systems are conveyed specifically to the inflamed gut mucosa where they exert their anti-inflammatory action. After intestinal absorption, these drugs are promptly and efficiently inactivated by the liver, so that only inactive molecules reach the systemic circulation. This review revises the main clinical trials, meta-analyses and observational studies conducted on traditional and newer steroids, and critically interprets the main results achieved by these studies.