Rifaximin Safety in Pediatric Patients
Rifaximin has NOT been established as safe or effective in children under 12 years of age for traveler's diarrhea, and is not approved for children under 18 years for hepatic encephalopathy or IBS-D, according to FDA labeling. 1
FDA-Approved Age Restrictions
The FDA drug label explicitly states that rifaximin's safety and effectiveness have not been established in: 1
- Pediatric patients less than 12 years of age for traveler's diarrhea
- Patients less than 18 years of age for hepatic encephalopathy and irritable bowel syndrome with diarrhea (IBS-D)
Off-Label Use in Pediatric Populations
Despite lack of FDA approval, rifaximin has been used off-label in children with specific conditions:
Inflammatory Bowel Disease (IBD)
- The IDSA/SHEA guidelines note that rifaximin has been used in younger children with refractory IBD and small intestinal bacterial overgrowth with few reports of adverse events, though this represents off-label use without robust efficacy data. 2
- A retrospective study of 23 pediatric IBD patients (median age 13 years) showed rifaximin was well-tolerated at doses of 10-30 mg/kg, with symptom improvement in diarrhea (60% within 4 weeks), abdominal pain (70.6% within 4 weeks), and bleeding (66.7% within 4 weeks). 3
Clostridium difficile Infection (CDI)
- For second or subsequent CDI recurrences in children, rifaximin may be considered as part of combination therapy (vancomycin for 10 days followed by rifaximin for 20 days), though the IDSA/SHEA guidelines note there is no pediatric dosing established and rifaximin is not FDA-approved for children under 12 years. 4
- This recommendation carries a weak strength with very low quality evidence. 4
Small Intestinal Bacterial Overgrowth (SIBO)
- A study of 50 IBS children showed rifaximin 600 mg daily for one week was effective and safe for SIBO treatment, with 64% normalization of breath tests, excellent compliance, and no relevant side effects. 5
Important Safety Profile
Rifaximin has an excellent safety profile with minimal systemic absorption and few adverse events reported in pediatric use, but concerns exist regarding antimicrobial resistance development. 2, 6
Key safety characteristics include: 7, 8, 6
- Negligible gastrointestinal absorption limiting systemic effects
- Low microbial resistance rates
- Minimal drug interactions
- Safe in all patient populations including young children (based on clinical experience, not FDA approval)
- No serious adverse events reported in pediatric studies
Critical Limitations
Rifaximin should NOT be used for invasive diarrheal pathogens or dysentery in children, as clinical failure rates reach up to 50% when invasive pathogens are present. 2, 8
Clinical Bottom Line
While rifaximin demonstrates a favorable safety profile in off-label pediatric use for specific conditions (IBD, SIBO, recurrent CDI), it lacks FDA approval and robust efficacy data for children under 12-18 years depending on the indication. 1 Use in pediatric patients represents off-label prescribing that should be reserved for specific clinical scenarios where standard therapies have failed, with careful consideration of the lack of established dosing and long-term safety data. 2