title: Repeat Treatment With Rifaximin Is Safe and Effective in Patients With Diarrhea-Predominant Irritable Bowel Syndrome.
abstract: Few treatments have demonstrated efficacy and safety for diarrhea-predominant irritable bowel syndrome (IBS-D). A phase 3, randomized, double-blind, placebo-controlled trial was performed to evaluate the safety and efficacy of repeat treatment with the nonsystemic antibiotic rifaximin.
  
  
  
  The trial included adults with IBS-D, mean abdominal pain and bloating scores of 3 or more, and loose stool, located at 270 centers in the United States and Europe from February 2012 through June 2014. Those responding to a 2-week course of open-label rifaximin 550 mg 3 times daily, who then relapsed during an observation phase (up to 18 weeks), were randomly assigned to groups given repeat treatments of rifaximin 550 mg or placebo 3 times daily for 2 weeks. The primary end point was percentage of responders after first repeat treatment, defined as a decrease in abdominal pain of ≥30% from baseline and a decrease in frequency of loose stools of ≥50% from baseline, for 2 or more weeks during a 4-week post-treatment period.
  
  
  
  Of 1074 patients (44.1%) who responded to open-label rifaximin, 382 (35.6%) did not relapse and 692 (64.4%) did; of these, 636 were randomly assigned to receive repeat treatment with rifaximin (n = 328) or placebo (n = 308). The percentage of responders was significantly greater with rifaximin than placebo (38.1% vs 31.5%; P = .03). The percentage of responders for abdominal pain (50.6% vs 42.2%; P = .018) was significantly greater with rifaximin than placebo, but not stool consistency (51.8% vs 50.0%; P = .42). Significant improvements were also noted for prevention of recurrence, durable response, and bowel movement urgency. Adverse event rates were low and similar between groups.
  
  
  
  In a phase 3 study of patients with relapsing symptoms of IBS-D, repeat rifaximin treatment was efficacious and well tolerated. ClinicalTrials.gov ID: NCT01543178.
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, Massachusetts. Electronic address: alembo@bidmc.harvard.edu.
authors.forename: Anthony
authors.initials: A
authors.lastname: Lembo
authors.affiliation: Cedars-Sinai Medical Center, Los Angeles, California.
authors.forename: Mark
authors.initials: M
authors.lastname: Pimentel
authors.affiliation: Regents University, Augusta, Georgia.
authors.forename: Satish S
authors.initials: SS
authors.lastname: Rao
authors.affiliation: University of Michigan, Ann Arbor, Michigan.
authors.forename: Philip
authors.initials: P
authors.lastname: Schoenfeld
authors.affiliation: University of South Alabama, Mobile, Alabama.
authors.forename: Brooks
authors.initials: B
authors.lastname: Cash
authors.affiliation: Washington University School of Medicine, Specialists in Gastroenterology, St. Louis, Missouri.
authors.forename: Leonard B
authors.initials: LB
authors.lastname: Weinstock
authors.affiliation: Salix Pharmaceuticals, Raleigh, North Carolina.
authors.forename: Craig
authors.initials: C
authors.lastname: Paterson
authors.affiliation: Salix Pharmaceuticals, Raleigh, North Carolina.
authors.forename: Enoch
authors.initials: E
authors.lastname: Bortey
authors.affiliation: Salix Pharmaceuticals, Raleigh, North Carolina.
authors.forename: William P
authors.initials: WP
authors.lastname: Forbes
mesh_terms: D015746:Abdominal Pain / Q000188:drug therapy / Q000209:etiology; D000328:Adult; D000890:Anti-Infective Agents / Q000009:adverse effects / Q000627:therapeutic use*; D003967:Diarrhea / Q000188:drug therapy / Q000209:etiology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000150:complications / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D019233:Retreatment; D012294:Rifamycins / Q000009:adverse effects / Q000627:therapeutic use*; D000078262:Rifaximin
chemical_list: D000890:Anti-Infective Agents; D012294:Rifamycins; D000078262:Rifaximin
keywords: Bloating; Functional Bowel Disease; Nonabsorbed; Xifaxan