New antibiotic therapy for IBS
Clinical trials conducted at Cedars-Sinai Medical Centre in Los Angeles and at the University of North Carolina found that two weeks of treatment with antibiotic rifaximin provides significant relief for irritable bowel syndrome symptoms (IBS), including bloating, abdominal pain and loose or watery stools.
In traditional therapies, IBS patients get benefit from medications only while on the drug. But, patients in the new study reported relief of their symptoms extended for weeks after completing treatment with rifaximin — a minimally absorbed antibiotic that stays in the gut.
The findings of the trials were published in the current issue of the New England Journal of Medicine.
Mark Pimentel, GI Motility Program director and chief investigator of the trials at Cedars-Sinai, said the findings showed that targeted antibiotics provide safe, effective and long-lasting relief for IBS that affects almost one in every 10 people worldwide.
“For years, the treatment options for IBS patients have been extremely limited,” Pimentel said.
“IBS often does not respond well to treatments currently available, such as dietary changes and fibre supplements alone.
“With this antibiotic treatment, the patients feel better, and they continue to feel better after stopping the drug. This means that we did something to strike at the cause of the disease.”
In two, 600-plus patient double-blind trials, patients with mild to moderate diarrhoea and bloating were randomly assigned to take a 550 milligram dose of rifaximin or placebo three times daily for two weeks.
Study participants were then followed for 10 weeks more.
About 40 per cent of patients who took the drug reported they had significant relief from bloating, abdominal pain and loose or watery stools. Further, that relief was sustained for weeks after they stopped taking the antibiotic.
Doctors commonly categorise IBS patients with a “constipation predominant” condition, a diarrhoea-predominant” condition, or an alternating pattern of diarrhoea and constipation. In addition, patients often experience abdominal pain or cramps, excess gas or bloating, and visible abdominal distension.
Because the cause of the disease had been elusive, treatments for the disease historically have focused on relieving its symptoms with medications that either slow or speed up the digestive process.
Earlier research by Pimentel and colleagues documents a link between bloating, the most common symptom, and bacterial fermentation in the gut related to small intestine bacterial overgrowth, or SIBO.
Rifaximin has currently been approved by the U.S. Food and Drug Administration to treat travellers’ diarrhoea and hepatic encephalopathy.