Rifaximin effective for repeat treatment of IBS with diarrhea

(HealthDay)—Repeat treatment with the nonsystemic antibiotic rifaximin is effective in patients with relapsing symptoms of diarrhea-predominant irritable bowel syndrome (IBS-D), according to a study published in the December issue of Gastroenterology.

Anthony Lembo, M.D., from the Beth Israel Deaconess Medical Center in Boston, and colleagues conducted a multicenter, phase 3, randomized, placebo-controlled trial to evaluate the safety and efficacy of repeat treatment with the nonsystemic antibiotic rifaximin (550 mg three times daily for two weeks) among 636 adults with IBS-D, mean abdominal pain and bloating scores of 3 or more, and loose stool (February 2012 through June 2014).

The researchers found that the percentage of responders was significantly greater with rifaximin than placebo (P = 0.03). For abdominal pain, the percentage of responders (P = 0.018) was significantly greater with rifaximin versus placebo, but not for stool consistency (P = 0.42). There were also significant improvements for prevention of recurrence, durable response, and bowel movement urgency. The groups had similar adverse event rates.

"In a phase 3 study of patients with relapsing symptoms of IBS-D, repeat rifaximin treatment was efficacious and well tolerated," the authors write.

Several authors disclosed financial ties to Salix Pharmaceuticals, which manufactures rifaximin and funded the study.