Rifaximin helps improve symptoms of IBS with diarrhoea

21 Mar 2023
Rifaximin helps improve symptoms of IBS with diarrhoea

Treatment with rifaximin appears to produce significant reductions in multiple, concurrent symptoms of irritable bowel syndrome (IBS) with diarrhoea, according to a study that uses a novel tri-symptom endpoint.

Researchers conducted post hoc analyses of two randomized, double-blind, placebo-controlled trials and the open-label phase of a randomized, double-blind, placebo-controlled trial. The trials involved adult participants with IBS-D who received a 2-week course of rifaximin 550 mg three times a day.

Endpoints included individual and composite responses for abdominal pain (mean weekly improvements from baseline of ≥30 percent, ≥40 percent, or ≥50 percent), bloating (mean weekly improvements from baseline of ≥1 or ≥2 points; or ≥30 percent, ≥40 percent, or ≥50 percent), stool consistency (mean weekly average stool consistency score <3 or <4), and urgency (improvement from baseline of ≥30 percent or ≥40 percent in percentage of days with urgency). These endpoints were evaluated for ≥2 of the first 4 weeks after treatment and then weekly for 12 weeks.

The total study population included 1,258 patients from the double-blind trials (rifaximin: n=624; placebo: n=634) and 2,438 from the open-label trial. Significantly more patients who received rifaximin vs placebo showed response for bloating or urgency (p≤0.03). The same was true for response for the composite abdominal pain and bloating (p<0.05).

The percentage of tri-symptom composite endpoint responders (abdominal pain, bloating, and faecal urgency) was also significantly greater in the rifaximin group than in the placebo group (p=0.001). Of note, significantly more rifaximin-treated participants significantly achieved response (≥30 percent composite tri-symptom threshold) as early as 1 week post-treatment, with significance maintained through ≥5 weeks after treatment.

Results for the open-label trial were consistent with those of the double-blind trials.

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