XIFAXAN is contraindicated in patients with a hypersensitivity to rifaximin, any of the rifamycin antimicrobial agents, or any of the components in XIFAXAN. Hypersensitivity reactions have included exfoliative dermatitis, angioneurotic edema and anaphylaxis.Clostridium difficile-associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including XIFAXAN and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon which may lead to overgrowth of C. difficile. If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. The most common adverse reactions occurring in greater than eight percent of patients in the clinical study were edema peripheral (15 percent), nausea (14 percent), dizziness (13 percent), fatigue (12 percent), ascites (11 percent), muscle spasms (nine percent), pruritus (nine percent) and abdominal pain (nine percent). About XIFAXAN ® (rifaximin) 200 mg tablets Rifaximin is a gut-selective antibiotic with negligible systemic absorption and broad-spectrum activity in vitro against both Gram-positive and Gram-negative pathogens. Rifaximin has a similar tolerability profile to that of placebo. Rifaximin tablets 200 mg, which Salix markets in the U.S. under the trade name XIFAXAN ® (rifaximin) tablets 200 mg, currently is approved for the treatment of patients, 12 years of age or older, with travelers' diarrhea (TD) caused by non–invasive strains of Escherichia coli. XIFAXAN should not be used in patients with diarrhea complicated by fever or blood in the stool or diarrhea due to pathogens other than Escherichia coli. XIFAXAN should be discontinued if diarrhea symptoms get worse or persist more than 24–48 hours, and alternative antibiotic therapy should be considered. In clinical trials, XIFAXAN was generally well-tolerated. The most common side effects (versus placebo) were flatulence 11.3 percent (versus 19.7 percent), headache 9.7 percent (versus 9.2 percent), abdominal pain 7.2 percent (versus 10.1 percent) and rectal tenesmus 7.2 percent (versus 8.8 percent). Rifaximin has been used in Italy for 25 years and is approved in 33 countries. Salix acquired rights to market rifaximin in North America from Alfa Wassermann S.p.A. in Bologna, Italy. Alfa Wassermann markets rifaximin in Italy under the trade name Normix ®. About APRISO ® APRISO™ is a locally-acting aminosalicylate indicated for the maintenance of remission of ulcerative colitis in patients 18 years and older. APRISO is contraindicated in patients with hypersensitivity to salicylates, aminosalicylates, or to any of the components of APRISO capsules. The recommended dose of APRISO is four 0.375 g capsules once daily in the morning (1.5 g/day) with or without food. Because dissolution of the coating of APRISO granules depends on pH, APRISO should not be coadministered with antacids. Patients with phenylketonuria should be aware that APRISO contains aspartame, equivalent to 0.56 mg of phenylalanine. In two well-controlled clinical trials, the most common treatment-related adverse events occurring in greater than 3% of adult patients taking 1.5 g/day of APRISO (versus placebo) were headache (11% vs. 8%), diarrhea (8% vs. 7%), upper abdominal pain (5% vs 3%), nausea (4% vs 3%), nasopharyngitis (4% vs 3%), influenza and influenza-like illness (4% vs 4%) and sinusitis (3% vs 3%).