Effects of rifaximin treatment and retreatment in nonconstipated IBS subjects

Recent evidence suggests a role for gut bacteria and antibiotics in the pathophysiology and treatment of irritable bowel syndrome (IBS), respectively. While the benefits of the antibiotic rifaximin have demonstrated efficacy and durable improvement in symptoms over 3 months, the long-term need for retreatment using this approach is mostly unknown. In this retrospective study, subjects with nonconstipated IBS who were retreated with rifaximin were examined.

Charts of patients who were seen at a tertiary care medical center between 2007 and 2011 were reviewed. After exclusion criteria were applied, subjects who had received rifaximin and were seen for retreatment were fully reviewed. During review, demographic information, duration of response, and success of treatment and retreatment were evaluated.

A total of 522 charts were reviewed. Of these 522 charts, 71 subjects were nonconstipated IBS subjects who had received at least one retreatment. Of these, 48 had a second, 22 had a third, 7 had a fourth, and 4 had a fifth treatment. More than 75% of subjects who initially responded to rifaximin also responded to any further retreatment, with no significant reduction in benefit for successive retreatments. Furthermore, there was no change in the duration of benefit (median time between treatments) for successive retreatments.

Retreatment with rifaximin for subjects with nonconstipated IBS in a real-world clinical practice was successful up to five times without decrease in duration or effect.