When do you use Rifaximin (rifamycin derivative antibiotic)?

Indications for Rifaximin Use in Clinical Practice

Rifaximin is primarily indicated for travelers' diarrhea caused by non-invasive pathogens, irritable bowel syndrome with diarrhea (IBS-D), and prevention of recurrent hepatic encephalopathy in patients with liver disease.

Travelers' Diarrhea

• Rifaximin (200 mg three times daily for 3 days) is effective for treating travelers' diarrhea caused by non-invasive diarrheagenic Escherichia coli 1, 2
• Rifaximin should NOT be used for travelers' diarrhea in areas where invasive pathogens are common (particularly Southeast and South Asia) due to limited efficacy against these organisms 1, 2
• Rifaximin is contraindicated for treatment of dysentery (bloody diarrhea) regardless of illness severity 2
• Rifaximin has an excellent safety profile due to minimal systemic absorption, making it safer than fluoroquinolones or azithromycin for non-invasive diarrhea 1, 2

Irritable Bowel Syndrome with Diarrhea (IBS-D)

• Rifaximin is FDA-approved for IBS-D at a dosage of 550 mg three times daily for 14 days 1
• Patients who experience recurrence of IBS-D symptoms after initial response can be retreated up to 2 times with the same dosage regimen 1
• Rifaximin showed significantly greater response based on the FDA responder endpoint for IBS-D compared to placebo (RR, 0.85; 95% CI, 0.78–0.94) 1
• Rifaximin demonstrated improvement in relief of bloating (RR, 0.86; 95% CI, 0.70–0.93) and abdominal pain (RR, 0.87; 95% CI, 0.80–0.95) in IBS-D patients 1

Hepatic Encephalopathy

• Rifaximin (550 mg twice daily) is recommended as an add-on therapy to lactulose for prevention of recurrent hepatic encephalopathy in cirrhotic patients 1, 3
• Rifaximin reduced the risk of recurrent hepatic encephalopathy by 58% compared to placebo when added to lactulose therapy 1, 3
• Rifaximin should be used alone for prevention of recurrent hepatic encephalopathy only when lactulose is poorly tolerated 1, 3
• First-line treatment for acute hepatic encephalopathy remains lactulose, with rifaximin added if lactulose alone fails in prevention 1, 3

Other Potential Uses

• Small intestinal bacterial overgrowth (SIBO) - emerging evidence supports rifaximin use 4, 5
• Uncomplicated diverticular disease - some evidence for prevention of recurrent diverticulitis 4
• Clostridium difficile infection - limited evidence for refractory or recurrent cases 6, 7

Safety Considerations

• Rifaximin has minimal systemic absorption, resulting in an excellent safety profile 8
• Most common adverse events in hepatic encephalopathy trials included peripheral edema (15%), nausea (14%), dizziness (13%), fatigue (12%), and ascites (11%) 8
• Most common adverse effects in IBS-D trials were abdominal pain, diarrhea, headache, and upper respiratory tract infection, occurring in <10% of patients 6
• Rifaximin has limited drug interactions due to minimal systemic absorption 8, 5

Important Precautions and Limitations

• Rifaximin should not be used for invasive or bloody diarrhea due to limited efficacy 1, 2
• For hepatic encephalopathy, always address precipitating factors first, then initiate lactulose before considering rifaximin 1, 3
• High cost of rifaximin may be a barrier to routine use, though benefits in reducing hospitalizations for hepatic encephalopathy may offset this cost 3
• Rifaximin has limited utility in severe hepatic encephalopathy (West-Haven grade 3 or higher) due to the need for oral administration 3