A randomized double-blind placebo-controlled trial of rifaximin in patients with abdominal bloating and flatulence.
OBJECTIVE
To study the efficacy of rifaximin, a nonabsorbable antibiotic, in relieving chronic functional symptoms of bloating and flatulence.


METHODS
Randomized double-blind placebo-controlled trial consisting of three 10-day phases: baseline (phase 1), treatment with rifaximin 400 mg b.i.d. or placebo (phase 2), and post-treatment period (phase 3). Primary efficacy variable was subjective global symptom relief at the end of each phase. A symptom score was calculated from a symptom diary. Lactulose H2-breath test (LHBT) was performed at baseline and end of study.


RESULTS
One hundred and twenty-four patients were enrolled (63 rifaximin and 61 placebo). Baseline characteristics were comparable and none had an abnormal baseline LHBT. Rome II criteria were met in 58.7% and 54.1%, respectively. At the end of phase 2, there was a significant difference in global symptom relief with rifaximin versus placebo (41.3% vs 22.9%, p = 0.03). This improvement was maintained at the end of phase 3 (28.6% vs 11.5%, p = 0.02). Mean cumulative and bloating-specific scores dropped significantly in the rifaximin group (p < 0.05). Among patients with IBS, a favorable response to rifaximin was noted (40.5% vs 18.2%; p = 0.04) persisting by the end of phase 3 (27% vs 9.1%; p = 0.05). H2-breath excretion dropped significantly among rifaximin responders and correlated with improvement in bloating and overall symptom scores (p = 0.01). No adverse events were reported.


CONCLUSIONS
Rifaximin is a safe and effective treatment for abdominal bloating and flatulence, including in IBS patients. Symptom improvement correlates with reduction in H2-breath excretion. Future trials are needed to examine the efficacy of long-term or cyclic rifaximin in functional colonic disorders.
Sharara
Ala I
AI
Gastroenterology Division, Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
Aoun
Elie
E
Abdul-Baki
Heitham
H
Mounzer
Rawad
R
Sidani
Shafik
S
Elhajj
Ihab
I
D000328:Adult; D001944:Breath Tests; D004311:Double-Blind Method; D005260:Female; D005414:Flatulence / Q000175:diagnosis / Q000188:drug therapy*; D005500:Follow-Up Studies; D005765:Gastrointestinal Agents / Q000627:therapeutic use*; D006801:Humans; D006859:Hydrogen / Q000032:analysis; D007792:Lactulose; D008297:Male; D012294:Rifamycins / Q000627:therapeutic use*; D000078262:Rifaximin; D016896:Treatment Outcome
D005765:Gastrointestinal Agents; D012294:Rifamycins; D007792:Lactulose; D006859:Hydrogen; D000078262:Rifaximin