Rifaximin is a semisynthetic, rifamycin-based non-systemic antibiotic. Very little of the drug will pass the gastrointestinal wall into the circulation as is common for other types of orally administered antibiotics. Rifaximin inhibits bacterial RNA synthesis by its action on the beta-subunit of the DNA-dependent RNA polymerase. It shows the same broad spectrum activity as rifamycin which exerts bactericidal action against many species of Gram-positive and Gram-negative, aerobic and anaerobic bacteria.
Contraindicated in patients with a hypersensitivity to Rifaximin or to any of the rifamycin antimicrobial agents, or any components of this product
Side effects include flatulence, headache, abdominal pain, rectal tenesmus, defecation urgency, nausea, constipation, pyrexia, vomiting. Reactions have been reported, including anaphylaxis, angioneurotic edema, and exfoliative dermatitis.
Pregnancy category C. It is not known whether Rifaximin is excreted in human milk or not.
Rifaximin is not found to be effective in patients with diarrhea complicated by fever and/or blood in the stools. Rifaximin therapy should be discontinued if diarrhea symptoms get worse or persist for more than 24-48 hours and alternative antibiotic therapy should be considered. Pseudomembranous colitis has been reported with nearly all antibacterial agents and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of antibacterial agents.
Renal Impairment: The pharmacokinetics of Rifaximin in patients with impaired renal function has not been studied.
Hepatic Impairment: The systemic exposure of Rifaximin was markedly elevated in patients with hepatic impairment compared to healthy subjects.
No specific information is available on the treatment of over dosage with Rifaximin. In case of over dosage, discontinue Rifaximin, treat symptomatically and institute supportive measures as required.
