Data show investigational antibiotic safe, effective in preventing travelers diarrhea
New data suggest the investigational drug rifaximin, a non-absorbed (less than .5%) antibiotic with few side effects and low potential for resistance, is effective in preventing travelers diarrhea, an illness that affects up to 60 percent of international travelers. Until now, antimicrobial prophylaxis, while effective, has been discouraged because of side effects and the encouragement of resistance. The study results, presented Sunday, May 16 at the 2004 Digestive Disease Week (DDW) annual meeting by lead investigator, Herbert L. DuPont, M.D., Chief of the Internal Medicine Service at St. Lukes Episcopal Hospital in Houston, showed that, over two weeks, 85 percent of the rifaximin-treated subjects remained free of diarrhea, compared with 49 percent of the placebo-treated subjects.
Dr. DuPont is also Director, Center for Infectious Diseases, University of Texas, Houston School of Public Health and Vice-Chairman, Department of Medicine at Baylor College of Medicine.
Travelers diarrhea threatens up to 50 million persons going to Mexico and Latin America, Africa and southern Asia each year. The illness can render travelers bed ridden for a full day or more, and considerably decrease their energy for up to a week or longer. In addition, a bout of travelers diarrhea can also cause chronic diarrhea and long-lasting irritable bowel syndrome in some people. The antibiotic, rifaximin, with the projected brand name of Xifaxan, is currently under review by the U.S. Food and Drug Administration. It has previously been shown by researchers to be a safe and effective form of therapy for treatment of travelers diarrhea in clinical studies conducted in Mexico, Peru, India and Kenya and has been prescribed internationally since 1987 and is currently approved in 17 countries worldwide.
"This is potentially one of the most important advances over the past 50 years toward reducing the occurrence of illness of travelers to the high-risk areas," said Dr. DuPont. "The characteristics of rifaximin — it is non systemic since it stays in the intestine after taking it by mouth and has been shown to be "gut-selective" in clinical trials — make it an ideal drug for prevention of diarrhea in international travelers. It particularly practical in that it was effective in preventing illness with as little as one dose a day."
About the Study
The randomized double-blind, placebo-controlled study evaluated the tolerability and efficacy of rifaximin as prophylaxis for travelers diarrhea. Two hundred and twenty U.S. college students were enrolled in the trial within 72 hours of their arrival in Guadalajara, Mexico. Study participants received 200 milligrams of rifaximin once daily, twice daily, three times daily or placebo for two weeks. Eleven students dropped out of the study, leaving 209 participants to be evaluated daily for three weeks for the occurrence of diarrhea, mild diarrhea or severe diarrhea, and for five weeks for drug related side effects.
Rifaximin protected the young adults from the U.S. against all forms of diarrhea and intestinal symptoms in all drug doses tested (one dose, two doses, or three doses per day). Over the two-weeks in Mexico, 85 percent of the rifaximin-treated subjects compared with 49 percent of the placebo-treated subjects remained free of diarrhea. In the groups not developing diarrhea, rifaximin also prevented the occurrence of milder forms of diarrhea and prevented the occurrence of moderate and severe abdominal pain and cramps and excessive gas-related symptoms. The drug was safe, having in incidence of adverse events comparable to placebo (inactive sugar pill used to blind the drug).
For a copy of the DDW abstract or for more information during the conference, please contact Dr. DuPont through his pager: 877-326-1401. After the conference, his office number in Houston is 832-355-4122.
The study was supported by a grant from Salix Pharmaceutical Company.
Digestive Disease Week (DDW) is the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery. Jointly sponsored by the American Association for the Study of Liver Diseases (AASLD), the American Gastroenterological Association (AGA), the American Society for Gastrointestinal Endoscopy (ASGE) and the Society for Surgery of the Alimentary Tract (SSAT), DDW takes place May 15-20, 2004 in New Orleans, Lousiana. The meeting showcases approximately 5,000 abstracts and hundreds of lectures on the latest advances in GI research, medicine and technology.
St. Lukes Episcopal Health System is a comprehensive health system that serves the primary and tertiary healthcare needs of the community. Established by the Episcopal Diocese of Texas, the System includes the flagship St. Lukes Episcopal Hospital in the Texas Medical Center, St. Lukes Episcopal Health Charities, St. Lukes Community Health Services, KS Management Services, LLP, and St. Lukes Community Medical Center (CMC)—The Woodlands. St. Lukes Episcopal Hospital is home to the world-renowned Texas Heart Institute, founded in 1962.
Corrie Murphy | EurekAlert!