Rifaximin
Rx Only
Generic NameRifaximin
Therapeutic ClassRifamycin Antibiotic
Common Dose200–550 mg
Max / 24h1650 mg
PregnancyCategory C
Indications ▼
Acute infectious diarrhea caused by non-invasive Escherichia coli
Hepatic encephalopathy (prevention of recurrence)
Irritable Bowel Syndrome with diarrhea (IBS-D)
Traveler’s diarrhea
Small intestinal bacterial overgrowth (off-label)
Mechanism & Pharmacokinetics ▼
Mechanism: Inhibits bacterial RNA synthesis by binding to the beta-subunit of DNA-dependent RNA polymerase, leading to suppression of bacterial growth in the gastrointestinal tract.
Pharmacokinetics: Poorly absorbed orally (<1% systemic absorption); acts locally in the gut; peak fecal concentrations achieved rapidly; minimal systemic metabolism; excreted mainly in feces.
Dosage & Administration ▼
| Indication | Recommended Dose | Duration |
|---|---|---|
| Traveler’s Diarrhea | 200 mg three times daily | 3 days |
| Hepatic Encephalopathy | 550 mg twice daily | Long-term |
| IBS-D | 550 mg three times daily | 14 days |
| Adults (General) | 200–550 mg per dose | As prescribed |
Note: Can be taken with or without food. Tablets should be swallowed whole.
Side Effects ▼
Common: Nausea, flatulence, abdominal pain, headache
Occasional: Constipation, dizziness
Rare: Hypersensitivity reactions, C. difficile-associated diarrhea
Contraindications ▼
Hypersensitivity to rifaximin or other rifamycins
Severe intestinal obstruction
Drug Interaction ▼
Minimal systemic drug interactions due to poor absorption
Caution with P-glycoprotein inhibitors
No clinically significant CYP enzyme inhibition
Pregnancy & Lactation ▼
Category C; use only if clearly needed
Breastfeeding: minimal absorption; caution advised
Clinical / Research Summary ▼
Effective gut-selective antibiotic with minimal systemic effects
Reduces recurrence of hepatic encephalopathy when combined with lactulose
Well tolerated for long-term use
Low risk of bacterial resistance due to limited absorption
Patient Counseling Points ▼
Complete the full course as prescribed
Report persistent diarrhea or fever
Maintain hydration during treatment
Do not use for bloody diarrhea unless advised
Storage & Handling ▼
Store below 30°C
Protect from moisture
Keep out of reach of children
Brand Names (Bangladesh & Global) ▼
Bangladesh:
Rixamin® 200 mg
Rifaxin® 200 mg
Rifaxin® 550 mg
Aximin® 200 mg
Aximin® 550 mg
Efaxim® 200 mg
Efaxim® 550 mg
Henlix® 200 mg
Henlix® 550 mg
Hepatab® 200 mg
Hepatab® 550 mg
Hepaximin® 200 mg
Hepaximin® 550 mg
Rifagut® 200 mg
Rifagut® 550 mg
Rifabac® 200 mg
Rifacol® 200 mg
Rifacol® 550 mg
Rifax® 200 mg
Rifexa® 200 mg
Rifexa® 550 mg
Xifamin® 200 mg
Global:
Medical Disclaimer: This content is for educational purposes only and should not be used as a substitute for professional medical advice.
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