Pouchitis: rifaximin

How well does rifaximin work?

Three small studies have looked at how well rifaximin works when it is used to treat pouchitis, and 1 small study has looked at using rifaximin to prevent pouchitis coming back after it has been treated.

One study that looked at using rifaximin to treat pouchitis included 18 people; almost all of them had tried antibiotics to treat their pouchitis but they had not got better. About half of the people in the study were given rifaximin for 4 weeks, and the other people were given a 'dummy' tablet (which didn't contain any antibiotics) instead. Two of the people given rifaximin got better, but the other 6 people who took it didn't get better. None of the people given the 'dummy' tablet got better. Because this study included only 18 people, it cannot reliably tell us whether rifaximin does or does not work for treating pouchitis, because the results may just have been due to chance.

The 2 other studies that looked at using rifaximin to treat pouchitis did not compare rifaximin with any other tablet; they just report what happened when some people were given rifaximin for pouchitis. The studies were very similar and included a total of 26 people with chronic pouchitis. None of the people had got better after taking antibiotics that are usually used first for treating pouchitis. The people in these 2 studies were given rifaximin along with another antibiotic (ciprofloxacin) for 2 weeks. Most people in both of these studies got better after taking both antibiotics together (16 of 18 people in 1 study, and 5 of 8 people in the other). However, because these 2 studies didn't include many people, and they did not compare rifaximin with any other treatments, they can't reliably tell us how good rifaximin is for treating pouchitis.

One other study included 51 people who had got better after taking antibiotics for their pouchitis, but once they stopped taking antibiotics, the pouchitis would come back. Therefore this study wanted to see whether taking rifaximin for a long period of time (from a few months up to 2 years) would stop these people from getting pouchitis again. After 3 months, 33 out of 51 people taking rifaximin were still well. Again, because this study didn't include many people, and it did not compare rifaximin with any other treatments, it can't reliably tell us how good rifaximin is at stopping pouchitis coming back after it has been treated.

What are the possible harms or side effects?

In these 4 small studies in people with pouchitis, rifaximin caused very few side effects. However, in other studies where rifaximin has been used to treat other conditions, common side effects noticed by more than 1 out of 100 people who took rifaximin have included dizziness and headaches, and tummy symptoms like pain, swelling, sickness, diarrhoea or constipation. As with several other antibiotics, there is the rare possibility that rifaximin could cause severe diarrhoea.