What is Xifaxin (rifaximin) primarily used to treat?

Xifaxin (rifaximin) is primarily used to treat hepatic encephalopathy, a condition that occurs when the liver is unable to remove toxins from the blood, leading to neurological disturbances. Xifaxin works by reducing the production of ammonia in the intestines, which is a key contributing factor to the development of hepatic encephalopathy. By altering the gut flora and inhibiting certain bacteria, Xifaxin helps lower the levels of ammonia, thereby improving symptoms and potentially preventing episodes of encephalopathy in at-risk patients.

While Xifaxin is also indicated for treating traveler's diarrhea caused by non-invasive strains of E. coli, its primary and more critical use is in managing hepatic encephalopathy. It’s important to note that the other options listed, such as prophylaxis for HIV patients and as an antiviral against influenza, do not apply to Xifaxin, as it is not used in those contexts. Therefore, the most accurate and relevant application of Xifaxin is in the treatment of hepatic encephalopathy.