What are the uses of Rifagut (rifaximin)?

Uses of Rifaximin (Rifagut)

Rifaximin is FDA-approved for treating travelers' diarrhea caused by non-invasive strains of Escherichia coli, reducing the risk of hepatic encephalopathy recurrence, and treating irritable bowel syndrome with diarrhea (IBS-D). 1

Approved Indications

Travelers' Diarrhea

• Rifaximin 200 mg three times daily for 3 days is indicated for treatment of travelers' diarrhea caused by non-invasive strains of Escherichia coli in adults and pediatric patients 12 years and older 1
• Rifaximin has demonstrated efficacy in shortening the duration of travelers' diarrhea without major alteration of aerobic fecal flora or significant side effects 2
• Important limitation: Not to be used in patients with diarrhea complicated by fever or blood in the stool, or diarrhea due to pathogens other than E. coli 1
• Rifaximin is less effective for treatment of invasive pathogens, with failure to achieve wellness in up to 50% of treated subjects 3

Hepatic Encephalopathy

• Rifaximin 550 mg twice daily is indicated for reducing the risk of overt hepatic encephalopathy recurrence in adults 1
• Rifaximin is recommended as an adjunct to lactulose for secondary prophylaxis following more than one episode of overt hepatic encephalopathy within 6 months of the first episode 4
• Patients treated with rifaximin and lactulose combination show better recovery from hepatic encephalopathy within 10 days (76% vs. 44%) and shorter hospital stays (5.8 vs. 8.2 days) compared to lactulose alone 4

Irritable Bowel Syndrome with Diarrhea (IBS-D)

• Rifaximin 550 mg three times daily for 14 days is indicated for treatment of IBS-D in adults 1
• Patients who experience recurrence of symptoms can be retreated up to 2 times with the same dosage regimen 1
• Rifaximin has demonstrated significantly greater response compared to placebo based on the FDA responder endpoint for IBS-D 3
• Rifaximin is associated with greater improvement in relief of bloating and abdominal pain in IBS-D patients 3

Off-Label Uses

Small Intestinal Bacterial Overgrowth (SIBO)

• Rifaximin has been successfully used in preliminary studies of small bowel bacterial overgrowth syndrome 2
• The drug's minimal systemic absorption makes it particularly suitable for treating localized gastrointestinal infections 5

Prevention of Travelers' Diarrhea

• Meta-analysis shows significant reduction in risk of travelers' diarrhea with rifaximin use compared to placebo (pooled RR 0.478,95% CI: 0.375-0.610) 6
• Rifaximin offers protection rates of 48-72%, with lower protection rates for Asian than Latin American countries 6
• Guidelines suggest rifaximin as first choice for prophylaxis in high-risk groups due to underlying health conditions or performance-critical occupation/itinerary 3

Diverticular Disease

• Emerging evidence suggests a possible beneficial effect of rifaximin in the treatment of uncomplicated diverticular disease and in the prevention of recurrent diverticulitis 7

Clinical Considerations and Cautions

• Rifaximin is a poorly absorbed antibiotic (less than 1% absorbed after oral administration) with minimal systemic side effects 2
• After three days of therapy, the average fecal level reaches approximately 8000 μg/g of stool 2
• Rifaximin has a broad spectrum of activity against Gram-positive, Gram-negative, and anaerobic bacteria 8
• Development of significant bacterial resistance appears to be unusual with rifaximin due to its minimal systemic absorption 2, 8
• For travelers' diarrhea in Southeast Asia, azithromycin is preferred over rifaximin due to higher prevalence of invasive pathogens in this region 3
• If rifaximin is given as first-line agent for travelers' diarrhea, azithromycin should also be provided in case of dysentery or febrile diarrhea 3

Rifaximin's unique properties as a gut-selective, minimally absorbed antibiotic with broad-spectrum activity make it valuable for treating various gastrointestinal conditions while minimizing systemic side effects and resistance development.