Can a child get too much Rifaximin? Are there toxic effects from using rifaximin over the long term?

One of the advantages of rifaximin is that little to no rifaximin enters the bloodstream, making it almost impossible for rifaximin to cause a side effect outside of the intestinal tract. Rifaximin has been used continuously in adults with severe liver disease for nearly 30 years, and no cumulative, long-term adverse effects of rifaximin have ever been noted.