title: Efficacy of rifaximin, a nonabsorbed oral antibiotic, in the treatment of small intestinal bacterial overgrowth.
abstract: BACKGROUND
  Rifamixin is an orally administrated, nonabsorbed antibiotic whose utility in eradication of small intestinal bacterial overgrowth (SIBO) is currently being evaluated.
  
  
  OBJECTIVE
  The aim of this study was to investigate efficacy and safety of rifaximin in relieving symptoms and normalizing the glucose breath test (GBT) in patients with SIBO.
  
  
  METHODS
  Symptom score assessment, consisting of frequency and severity of bloating, gas, abdominal pain, and bowel movements and the GBT were performed before and after treatment with rifaximin 800 mg/d for 4 weeks.
  
  
  METHODS
  Twenty consecutive symptomatic patients (16 women and 4 men; mean age, 47.8 years; range, 19 to 85 years) who had a positive GBT were prospectively studied in an open-labeled fashion. Fourteen patients (70.0%) presented with diarrhea, 3 (15.0%) with bloating and gas, and 3 (15.0%) with constipation as the dominant symptom.
  
  
  RESULTS
  : Eleven patients were hydrogen producers, 8 exclusively methane, and 1 patient produced both gases by the GBT. Among patients with diarrhea, 12 of 14 (85.7%) reported improvement in symptom scores of more than 50%; 1 between 25% and 50%, 1 had no response after 4 weeks of rifamixin. Among patients with bloating and gas or constipation as the main symptom: 2 of 6 (33.3%) had improvement between 50% and 75%; 3 (50%) had 25% to 50% improvement, and 1 (16.7%) had no response. Repeat GBT at the end of the 4 weeks showed that 54.5% of hydrogen formers and 50.0% of methane producers were eradicated, and there was a significant reduction (P <0.05) in the area under the concentration-time curve and peak values. No adverse effects were observed.
  
  
  CONCLUSIONS
  Rifaximin in a dose of 800 mg per day for 4 weeks: 1) was safe and effective treatment in reducing symptoms in patients with SIBO of multiple etiologies, especially when diarrhea was the dominant symptom; and 2) normalized the GBT in approximately 50% of patients. Data support a future therapeutic role for rifaximin in SIBO.
authors.affiliation: Department of Internal Medicine, Center for Gastrointestinal Nerve and Muscle Function, School of Medicine, The University of Kansas Medical Center, Kansas City, Kansas, USA.
authors.forename: Marek
authors.initials: M
authors.lastname: Majewski
authors.forename: Savio C
authors.initials: SC
authors.lastname: Reddymasu
authors.forename: Sandra
authors.initials: S
authors.lastname: Sostarich
authors.forename: Pernilla
authors.initials: P
authors.lastname: Foran
authors.forename: Richard W
authors.initials: RW
authors.lastname: McCallum
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000188:drug therapy*; D001944:Breath Tests; D005260:Female; D005765:Gastrointestinal Agents / Q000627:therapeutic use*; D005767:Gastrointestinal Diseases / Q000188:drug therapy / Q000382:microbiology; D006801:Humans; D006859:Hydrogen / Q000378:metabolism; D007421:Intestine, Small / Q000382:microbiology*; D008297:Male; D008697:Methane / Q000378:metabolism; D008875:Middle Aged; D012294:Rifamycins / Q000627:therapeutic use*; D000078262:Rifaximin; D016896:Treatment Outcome
chemical_list: D000890:Anti-Infective Agents; D005765:Gastrointestinal Agents; D012294:Rifamycins; D006859:Hydrogen; D000078262:Rifaximin; D008697:Methane