A Trial to Compare Xifaxan to Vancomycin for the Treatment of Clostridium Difficile-Associated Diarrhea (CDAD)

Clostridium difficile is a bacterium that proliferates when normal colonic flora have been altered, most commonly due to antibiotic use. Clostridium difficile is non-invasive and localized to the lumen of the colon. Once established, it produces 2 potent toxins, A and B. The principal reservoir for Clostridium difficile is the hospital environment, with the risk of acquiring Clostridium difficile increasing in direct proportion to the length of hospital stay.

Patients with CDAD typically present with profuse watery or mucoid diarrhea and cramping abdominal pain. Additional symptoms include fever, nausea, anorexia, malaise, and bloody stool. More severe cases may be complicated by dehydration, electrolyte disturbances, ileus, and peritonitis. Systemic manifestations may include prerenal azotemia, sepsis syndrome, and toxic colitis. White blood cell counts (WBCs) also may be markedly elevated with a shift to immature forms. Extreme presentation of fulminant colitis may require a colectomy and even result in death. Symptoms of CDAD may begin a few days after initiation of antibiotic therapy or up to 8 weeks after its discontinuation.

Inclusion criteria

• Subject is 18 years of age or older, has acute diarrhea and at least 1 other sign of enteric infection present, such as fever, nausea/loss of appetite, vomiting, severe abdominal pain or discomfort.
• Subject has a positive Clostridium difficile stool toxin assay at screening

Exclusion criteria

• Subject has had a previous episode of clinically diagnosed Clostridium difficile within the past 6 months.
• Subject has chronic diseases associated with diarrhea (e.g., inflammatory bowel disease or diarrhea predominant irritable bowel syndrome [DIBS])
• Subject has had any therapy with any agent administered for the treatment of Clostridium difficile prior to randomization.