Rifaximin in the treatment of inflammatory bowel disease.

The gut microbiota plays a role in promoting and maintaining inflammation in inflammatory bowel diseases (IBD), hence the rationale for the use of antibiotics in the treatment of those disorders. Antibiotics, however, may induce untoward effects, especially during long-term therapy. Rifaximin α polymer is an antibacterial agent that is virtually unabsorbed after oral administration and is devoid of systemic side effects. Rifaximin has provided promising results in inducing remission of Crohn's disease (up to 69% in open studies and significantly higher rates than placebo in double blind trials) and ulcerative colitis (76% in open studies and significantly higher rates than placebo in controlled studies) and might also have a role in maintaining remission of ulcerative colitis and pouchitis. The potential therapeutic activity of rifaximin in IBD deserves to be further investigated and confirmed in larger, controlled studies. The optimal dosage still needs to be better defined.