2 Weeks of Antibiotic Therapy Relieves IBS
Study Shows Rifaximin Helps Ease Symptoms of Irritable Bowel Syndrome
Rifaximin for IBS: Second Opinion
In an editorial published with the study results, Jan Tack, MD, PhD, a professor of medicine at University Hospital of the University of Leuven in Belgium, writes that "The TARGET studies have some attractive findings," including the sustained benefits and short treatment course.
It also seems to relieve the bloating, which he calls one of the most challenging symptoms.
But he has some caveats -- calling for more studies before the drug is widely used.
In an email interview, he says his main concern is antibiotic resistance -- so far not shown to be a problem in research studies -- and that the study follow-up needs to be longer.
"This issue is relatively easy to address with a longer-term follow-up study or a retreatment trial," he tells WebMD.
For now, he suggests that the antibiotic be reserved for those patients in whom overgrowth of the small intestine bacteria has been confirmed, or to limit treatment to a single cycle for those not responding to other medications.
Tack has severed as a scientific adviser to companies evaluating IBS drugs.
Another doctor, Christine Frissora, MD, an associate professor of medicine at Weill Cornell Medical College of Cornell University, says the results ''show promise."
She was not involved in the studies but has been prescribing rifaximin for IBS patients with the non-constipation form “off-label.” Off-label refers to uses that have not been approved by the FDA.
As for the new study findings, she says, "they won't change my practice but they will probably encourage other doctors to try it, especially primary care doctors who may not [yet] know about this data."
"The patients who have diarrhea, cramping, urgency and frequency, gas and bloating will be most likely to respond," she says.
It could also work, she says, in those with constipation. "We just don't know yet."
Pimentel says he is studying those patients now.
Frissora reports research funding from Tioga Pharmaceuticals for a study of an IBS drug and serving on the speakers bureaus for Prometheus Therapeutics and Diagnostics, Salix Pharmaceuticals, and Takeda Pharmaceuticals North America.