Rifaximin: A new treatment for travelers' diarrhea

OBJECTIVE: To review the pharmacology, pharmacokinetics, clinical efficacy, adverse effects, drug interactions and precautions, and dosing recommendations of rifaximin, a new nonabsorbed antimicrobial agent for travelers' diarrhea. DATA SOURCES: A MEDLINE search (1966-July 2004) was conducted to extract human and animal research data in the English language on rifaximin. STUDY SELECTION AND DATA EXTRACTION: Randomized, double-blind, placebo-controlled trials were reviewed and included to evaluate the efficacy of rifaximin in the treatment of travelers' diarrhea. DATA SYNTHESIS: Rifaximin is approved for the treatment of travelers' diarrhea in patients greater than or equal to 12 years of age with diarrhea caused by noninvasive strains of Escherichia coli. Rifaximin was superior to placebo and trimethoprim/sulfamethoxazole and equivalent to ciprofloxacin in the primary clinical endpoint of the time to the last unformed stool passed. CONCLUSIONS: Rifaximin is a viable alternative to ciprofloxacin for the treatment of travelers' diarrhea. As rifaximin is not systemically absorbed, it offers the advantage of leading to the development of less resistance compared with systemically absorbed antibiotics, in addition to fewer systemic adverse effects and drug interactions. However, the potential for cross-resistance between rifaximin and rifampin, as well as with other classes of antibiotics, is of concern and needs to be elucidated.