Travelers' diarrhea causes substantial morbidity and postinfectious irritable bowel syndrome.
Dr Herbert DuPont and colleagues designed a randomized, double-blind, placebo-controlled trial to evaluate nonabsorbable rifaximin for prevention of travelers' diarrhea.
The researchers included 210 US students to participate in the study in Guadalajara, Mexico.
The team gave the participants, on arrival in Mexico, rifaximin of 200 mg/d, 200 mg twice daily, or 200 mg 3 times daily or placebo for 2 weeks.
The research team followed participants daily for 3 weeks for enteric disease and symptoms and daily for 5 weeks for drug side effects.
The investigators also studied changes in intestinal coliform flora.
The researchers found that travelers' diarrhea developed in 15% of participants taking rifaximin and 54% of those taking placebo.
| Diarrhea developed in 15% with rifaximin versus 54% with placebo|
|Annals of Internal Medicine|
The investigative team noted that rifaximin provided 72% and 77% protection against travelers' diarrhea and antibiotic-treated travelers' diarrhea, respectively.
The team observed that all rifaximin doses were superior to placebo.
In the groups that did not report travelers' diarrhea, rifaximin significantly reduced the occurrence of mild diarrhea, moderate and severe intestinal problems.
The researchers reported that rates of adverse events were comparable in the rifaximin and placebo groups.
In addition, the team found minimal changes in coliform flora during rifaximin therapy.
The investigators reported that rifaximin safely prevented travelers' diarrhea in Mexico, where most cases are caused by diarrhea-producing Escherichia coli.
Dr DuPont concludes, “Rifaximin prevents travelers' diarrhea with minimal changes in fecal flora, and more liberal chemoprophylaxis against this disease should be considered.”
“Future studies should evaluate whether rifaximin is effective in preventing postinfectious irritable bowel syndrome.”
“A study is also needed in Asia to determine whether rifaximin can prevent diarrhea caused by invasive bacterial pathogens.”