 Tell your doctor if you are pregnant, plan on becoming pregnant, are nursing, if you have liver disease, taking warfarin or other medications. Some medications may increase the amount of Xifaxin in your body. Most common side effects are nausea and an increase in liver enzymes. Xifaxin. There's a deal on your fave just waiting for you in the McDonald's app. It's just sitting there right now. Come on. You can't leave it hanging like that. Your favorite thing for less?