Rifaximin for the Treatment of Irritable Bowel Syndrome

This study has been completed.
University of Chicago
Valeant Pharmaceuticals International, Inc.
Information provided by:
Cedars-Sinai Medical Center
ClinicalTrials.gov Identifier:
First received: November 25, 2005
Last updated: March 17, 2008
Last verified: July 2003
We have recently shown that the majority of patients with irritable bowel syndrome (IBS) have an abnormal lactulose breath test to suggest the presence of bacterial overgrowth of the small intestine. In open label and double blind treatment of IBS subjects with antibiotics, a dramatic improvement in clinical symptoms are observed. In these studies, the antibiotic chosen was neomycin, which is noted to have an efficacy of 20-25% in normalizing the lactulose breath test. A more efficacious antibiotic is needed. Therefore the aim of this study is to determine the efficacy of rifaximin in normalizing the lactulose breath test in IBS subjects with concomitant improvement in clinical symptoms.

Condition Intervention Phase
Irritable Bowel Syndrome
Drug: Rifaximin
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double-Blind
Primary Purpose: Treatment
Official Title: Rifaximin in the Treatment of Small Intestinal Bacterial Overgrowth and IBS: Double Blind Randomized Controlled Trial (Multicenter Trial)

Resource links provided by NLM:

Further study details as provided by Cedars-Sinai Medical Center:

Primary Outcome Measures:
  • Global improvement in IBS

Secondary Outcome Measures:
  • Improvement in abdominal pain, diarrhea, constipation and bloating

Estimated Enrollment: 92
Study Start Date: July 2003
Study Completion Date: January 2007
Primary Completion Date: January 2007 (Final data collection date for primary outcome measure)
  Show Detailed Description


Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Subjects will be selected for all studies based on the Rome I criteria. This will be the preferred method of identifying IBS patients to avoid pre-selecting patients with C- IBS. The goal is to evaluate methane as the determinant of transit, not constipation or diarrhea symptoms as through Rome II criteria. All subjects who are receiving a prokinetic drug at the time of enrollment will need to have a washout period of 7 days before starting the study protocol. Subjects will be identified through advertising in printed media and through the clinical operations of the GI motility program at Cedars-Sinai Medical Center.

Exclusion Criteria:

  • Subjects with a history of inflammatory bowel disease, diabetes, previous intestinal surgery, cirrhosis, celiac disease, probiotic use, current proton pump inhibitor use, recent antibiotic use (past 3 months), history of bowel obstruction, narcotic use or age greater than 65 years will be excluded. Most of these conditions are known to influence enteric bacteria levels. Women of childbearing years will undergo pregnancy testing before participating in the study (See below for details on the pregnancy test used). Women with positive pregnancy tests will be excluded.
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00259155

Sponsors and Collaborators
Cedars-Sinai Medical Center
University of Chicago
Valeant Pharmaceuticals International, Inc.
Principal Investigator: Mark Pimentel, MD Cedars-Sinai Medical Center
  More Information

ClinicalTrials.gov Identifier: NCT00259155     History of Changes
Other Study ID Numbers: 4166 
Study First Received: November 25, 2005
Last Updated: March 17, 2008
Health Authority: United States: Food and Drug Administration

Keywords provided by Cedars-Sinai Medical Center:
Irritable bowel syndrome, Bacterial overgrowth

Additional relevant MeSH terms:
Irritable Bowel Syndrome
Colonic Diseases
Colonic Diseases, Functional
Digestive System Diseases
Gastrointestinal Diseases
Intestinal Diseases
Anti-Infective Agents
Gastrointestinal Agents
Pharmacologic Actions
Therapeutic Uses

ClinicalTrials.gov processed this record on May 02, 2016