Additional Relevant Details XIFAXAN is 550mg rifaximin tablets, designed to treat IBS-D and reduce the risk of overt hepatic encephalopathy.  

Based on available information, Allergan believes it is the "first applicant" to file an ANDA for the generic version of XIFAXAN® 550 mg and, should its ANDA be approved, may be entitled to 180 days of generic market exclusivity.