From the Guidelines
Rifaximin is most effective for treating traveler's diarrhea caused by non-invasive bacterial pathogens, particularly E. coli, and is also useful in managing irritable bowel syndrome with diarrhea (IBS-D). It works by inhibiting bacterial RNA synthesis, preventing bacterial growth and replication without being significantly absorbed into the bloodstream. The standard dosage for traveler's diarrhea is 200 mg three times daily or 400 mg twice daily for 3 days 1. Rifaximin is particularly valuable because it acts locally in the gut with minimal systemic absorption, resulting in fewer side effects compared to other antibiotics. It's also useful in managing IBS-D at 550 mg three times daily for 14 days, and in preventing hepatic encephalopathy recurrence in liver disease patients at 550 mg twice daily long-term 1. However, rifaximin is not appropriate for diarrhea accompanied by high fever or blood in stool, which may indicate invasive pathogens requiring different antibiotics. It's also contraindicated in patients with hypersensitivity to rifamycin antibiotics. Common side effects include nausea, flatulence, and headache, though these are generally mild due to its limited systemic absorption. Some key points to consider when using rifaximin include:
- It is effective against non-invasive bacterial pathogens, particularly E. coli 1.
- It is useful in managing IBS-D and preventing hepatic encephalopathy recurrence 1.
- It is not appropriate for diarrhea accompanied by high fever or blood in stool 1.
- It is contraindicated in patients with hypersensitivity to rifamycin antibiotics 1.
- Common side effects are generally mild and include nausea, flatulence, and headache 1.
From the FDA Drug Label
XIFAXAN is a rifamycin antibacterial indicated for: • Treatment of travelers’ diarrhea (TD) caused by noninvasive strains of Escherichia coli in adult and pediatric patients 12 years of age and older (1.1) • Reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults (1.2) • Treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults (1. 3)
Rifaximin helps in diarrhea by treating travelers’ diarrhea (TD) caused by noninvasive strains of Escherichia coli and irritable bowel syndrome with diarrhea (IBS-D). It is more useful in:
- Travelers’ diarrhea caused by noninvasive strains of Escherichia coli
- Irritable bowel syndrome with diarrhea (IBS-D) It is not effective in diarrhea complicated by fever and/or blood in the stool or diarrhea due to pathogens other than E. coli 2
From the Research
Mechanism of Action
- Rifaximin is a gastrointestinal-selective antibiotic with a broad spectrum of antimicrobial activity, making it effective against non-invasive bacterial strains 3, 4.
- It has negligible systemic absorption (<0.4%), which reduces the risk of developing bacterial resistance and minimizes drug interactions 3, 5.
Efficacy in Diarrhea
- Rifaximin is effective in treating traveler's diarrhea caused by non-invasive Escherichia coli strains 3, 4, 5, 6.
- It is superior to placebo and equivalent to ciprofloxacin in reducing the duration of diarrhea 3, 5, 6.
- Rifaximin is also effective in treating diarrhea caused by other non-invasive bacterial strains, but its efficacy against invasive or inflammatory enteropathogens is limited 3, 4.
Type of Diarrhea
- Rifaximin is more useful in treating traveler's diarrhea caused by non-invasive bacterial strains, particularly Escherichia coli 3, 4, 5, 6.
- It is not effective against invasive or inflammatory enteropathogens, and alternative antibiotics should be used in such cases 3, 4.