irritable bowel syndrome with diarrhea (ibs-d) rifaximin re-treatment study

Conditions: Irritable Bowel Syndrome With Diarrhea

Summary: this study will evaluate the effectiveness and safety of repeat treatment with rifaximin 550 mg three times a day in patients with ibs with diarrhea who respond to initial treatment of rifaximin 550 mg three times a day.

it is important in chronic conditions to have information about how a product that is intended for short course administration in order to confer prolonged benefit should be administered beyond the first cycle of use once symptoms reappear. this phase 3 study will evaluate the efficacy and safety of repeat treatment with rifaximin 550 mg three times daily (tid) for 14 days in subjects with ibs-d who respond to an initial treatment course with rifaximin 550 mg tid for 14 days. this study consists of several treatment phases outlined below: screening/treatment 1 phase. subjects will receive single-blind placebo tid for 7-13 days and answer daily ibs symptom-related questions. treatment 2 phase. eligible subjects will receive open-label rifaximin 550 mg tid for 2 weeks with a 4-week treatment-free follow-up. responders will continue into maintenance phase 1. nonresponders will withdraw from the study. maintenance phase 1. subjects will continue the treatment-free follow-up period for up to 18 weeks until either: 1) they experience recurrence or 2) enrollment is met in the treatment 3 phase (double blind repeat treatment phase). subjects who do not meet recurrence criteria by the end of the maintenance phase 1 will withdraw from the study. treatment 3 phase/ double blind repeat treatment phase. subjects who meet criteria for recurrence will be randomized 1:1 to receive either rifaximin 550 mg tid or placebo tid for 2 weeks with a 4-week treatment-free follow-up. primary efficacy analysis will be performed at the end of the treatment 3 phase (at week 6 of the double-blind period). maintenance phase 2. all subjects continued into an additional treatment-free follow-up period of up to 6 weeks (maintenance phase 2). treatment 4 phase/second repeat treatment phase. subjects will receive the same double-blind treatment as previously assigned in the treatment 3 phase for 2 weeks with a 4-week treatment-free follow-up. a lactulose breath test sub-study will be conducted at select sites.

Eligibility criteria:
inclusion criteria: * ibs confirmed by rome iii diagnostic criteria. * at least 18 years of age. * colonoscopy within the past 10 years to rule out inflammatory bowel disease; or flexible sigmoidoscopy if \ 10 years prior. * willing to maintain a stable diet. including vitamins, supplements, and nutraceuticals. exclusion criteria: * diabetes (type 1 or 2). * lactose intolerance and not controlled by a lactose-free diet. * pregnant or planning to become pregnant or is lactating. * history of hiv or hepatitis b or c. * participation in investigational study within past 30 days. * taking rifaximin or any other antibiotic within past 60 days. * unstable cardiovascular or pulmonary disease, with change in treatment in last 30 days due to worsening disease condition. * history of gi surgery.

Keywords: ibs ibs-d ibs with diarrhea diarrhea irritable bowel syndrome with diarrhea