Systematic review: does concurrent therapy with 5‐ASA and immunomodulators in inflammatory bowel disease improve outcomes?

SummaryBackground With greater use of immunomodulators in inflammatory bowel disease (IBD), it is uncertain whether concurrent therapy with both 5‐aminosalicylic acid [5‐ASA, mesalazine (mesalamine)] and an immunomodulator is necessary.Aim To determine whether concurrent therapy with both 5‐ASA and immunomodulator(s) improves outcomes in IBD.Methods Systematic review with search terms ‘azathioprine, 6‐mercaptopurine, thiopurine(s), 5 aminosalicylic acid, mesalazine, inflammatory bowel disease, ulcerative colitis, Crohn’s disease, immunosuppressant(s), immunomodulator and methotrexate’ in November 2007 to identify clinical trials on concurrent 5‐ASA and immunomodulator therapy.Results Two small controlled studies were found. Neither showed a benefit on disease control beyond immunomodulator monotherapy. Potential pharmacological interactions exist between 5‐ASA and thiopurines. Whilst circumstantial, epidemiological and laboratory evidence suggests that 5‐ASA may assist colorectal cancer (CRC) chemoprevention, it may simply be via anti‐inflammatory effects. With changes in practice, ethical issues and the long lead‐time needed to demonstrate or disprove an effect, no clinical studies can/will directly answer this. The costs of avoiding one CRC in IBD may be as low as 153 times the annual cost of 5‐ASA therapy.Conclusions It is unclear whether concurrent 5‐ASA and immunomodulator therapy improves outcomes of disease control, drug toxicity or compliance. Concurrent therapy of 5‐ASA and immunomodulators may decrease CRC risk at ‘acceptable’ cost.