Summary contentEducational objectives:
1. To understand the role of 5-ASA in the treatment of IBD and the most frequent mistakes made in 5-ASA treatment
2. To review the evidence for dosing and treatment routes for the different localizations of inflammation in UC and CD
3. To emphasise the role of rectal 5-ASA therapy in proctitis and left sided colitis and the important role of oral/rectal combination therapy
4. To have an overview over optimal treatment strategies with 5-ASA
Inflammatory bowel disease (IBD) are chronic diseases affecting different segments of the digestive tract, also associated with extra-intestinal sites of inflammation. Global research has more intensively focused in developing novel pharmaceutical agents the last 30 years, due to a gradual increase in incidence and prevalence of IBD. 5-aminosalicylic acid (5-ASA) represent one of the older drug classes used for the treatment of IBD patients. The exact mechanism of action has not been elucidated. Proposed mechanisms are: (A) modulation of the inflammatory response originating from the cyclooxygenase and lipooxygenase pathways leading to a decrease of the synthesis of prostaglandins and leukotrienes, (B) interference with the production of inflammatory cytokines via decreasing the activity of nuclear factor κB, and inhibiting tumor necrosis factor and (C) interference with cellular functions of mucosal lymphocytes, macrophages, and natural killer cells. Properties of free radical scavengers and antioxidants have also been postulated. 5-ASA are recommended for the induction and maintenance of remission in mild-to-moderately active ulcerative colitis but are also used in cases with mild Crohn’s disease, although this practice is rather originating from uncontrolled observational data or expert opinion-based and not a formal recommendation in most of the major national or international guidelines. Oral and rectal formulation of 5-ASA exist and the choice of the most appropriate regimen depends on disease extent, localization and severity, the sites of the digestive tract that each formulation is released and patient’s preference. In general, a combination of both formulations is considered the most potent treatment. Safety profile is acceptable with the vast majority of the adverse events being reversible. Monitoring includes principally renal and hepatic function and complete blood count. 5-ASA are relatively fast acting drugs for symptom relief. However, remission may need up to 4-6 weeks to establish. Thus, timely design of optimal treatment strategies with 5-ASA is of utmost importance.